I am 11" taller than you and 27 years younger. My gravel bike is 650mm stack and 405mm of reach with 35mm of spacers and a -7deg stem.

What do my stats have to do with this discussion?...nothing, same as yours.

The 54T has 589mm of stack and 383mm of reach.
The 56R has 572mm of stack and 397mm of reach.
The 56T has 610mm of stack and 385mm of reach.

So the OP is comparing the 54T frame size with the 56T frame size.

I am 4” shorter than my dad and 3 years older than my wife. My mountain bike has a reach of 450mm and a stack of nobody-cares-about-MTB-stack-just-use-a-riser mm.

I hope the OP leaned something, here.

Sorry I wasn't clear. I'm saying the published specs contain the typo. Considering the difference in TT lengths as well as the ST angles and HT angles, having only a 2mm difference in reach sounds mathematically impossible. I suspect the company meant (edit: see below) for the 56T.

edit: ok I crunched the numbers and if I did it correctly, the reach should be about 391-392.

Thank you. Direct and to the point answering the actual questions!

I don't think so, but you are free to look. The geometries are on their site. The 54T and 56T. Unfortunately I can't post the link because I'm new, but it's under "find your fit" then "frame geometries"

Edit: I just saw your post above. You think the company made an error? Strange because they are emailing with me and quoted the same 385mm for the 56T in those emails.

Thanks for pointing this out. I notice this on forums all the time where people use someone's question as a means to talk about themselves. No offense to anyone, but it's just annoying.
I have a curve in my spine, both top and bottom of the spine. Not left right but front to back. It's called hyperlordoris and hyperkyphosis if anyone is interested. But anyway, this effectively takes a few inches off my torso. I'd probably be 5'11 without these curves. So everyone has different anatomy. The curves also make flexibility an issue. This is why I want to ride upright. I'm 162lbs and can cycle 100 miles. I don't consider myself unfit. But I do lack some flexibility due to the mentioned issues. It's my right to want to be upright! :D

Typos happen, but it seems odd for the typo to stay for multiple years and models as this is a smaller brand that is very heavy on informational materials. They have been very involved in releasing frame details thru the years and they clearly rely on the nerd side of things as a marketing approach. I think they are on the 3rd version of this frame(I own a v1) and the geometry has not changed. You would think someone in the last few years would have complained.

Yeah, I found it on Geometry Geeks, but it's the same numbers. My logic (with a slight adjustment for my error in calculating compact geometry) is this:
The top tube is 13mm longer but with an extra 0.5 degree more laid back seatpost.
The reach should be calculated at the same height as the theoretical top tube, 560mm up the seat tube from the BB*
Basic geometry calculations say that eats up 4.8mm of the extra top tube length, leaving 8.2mm to be taken up at the front

*Note that this does not account for the fact that your seat height is relative to the BB. not the top of the seat tube, but that only accounts for another 0.1mm

Any actual experts on frame geometry wanna tell me if I'm right or wrong?

I'm probably wrong. As you can see, I edited my calculations twice already for errors I caught, so maybe there's something more I'm missing. It still seems strange, the jumps between sizes (12mm from 51T to 54T, 9mm from 56T to 58T, 16mm from 58T to 61T, but only 2mm from 54T to 56T), but you do make a very good point, especially with the company emailing the OP back supporting that number.

I am another fan of adjusting reach with the stem, not the bars. I pick bars for hand comfort. I want contact points that are right on for wrist angle and the right relationship between lever position, tops and drops. Those put the bar reach, drop and curvature shape in a narrow range. Stems are an easy to change, systematically variable way to put those bars just where I want them.

My logic was if I go to a 70mm stem the handling would become poor, and my knees would get closer to the bars themselves. So by using the bars for a 10mm reduction, I'd get that reach without the negative effects.
Maybe I'm wrong, though. It would be nicer to get the hoods closer since I have relatively small hands, and without getting the bar itself closer to my knees.

Well, you ARE wrong about the handling for the reason I have explained numerous times. The effect on the bikes handling will be identical.

Are you actually worried about hitting your knees on the tops of the bar?

I dunno. I've ridden road bikes with 60mm to 120mm stems and didn't notice any handing issues that would concern me. That being said, if you're happy with where your tops are but want a shorter reach on the hoods, a handlebar can correct that.

As others have said, don't sweat the handling. Knees hitting the bars is an issue I've seen on a few bikes that otherwise fit. What I have found is that I can change the spacers under the bars by X amount and the horizontal reach of the stem by 2X and my position on the bike doesn't change. So, knees hit? 1 cm more spacer and 2 cm more reach. Plenty of clearance. My arm bends hasn't changed, nor has my back and shoulder position. (I ride with a low back. Someone who sits up a more might be closer to 1:1.)

I ride a flat bar and could be wrong but may be a zero setback seatpost could help reduce the reach.

The saddle fore/aft position should not be used to reduce reach. If you're too far forward relative to the crank, it will put too much weight on your hands.
Even though I have a short torso, I use either a 25 or 32mm setback post. If you're properly balanced, you should be able to hover your hands over the brake hoods, without too much effort. Improper balance over the saddle is often what leads riders down the path to lots of spacers and a high rise stem. The more upright position improves the balance, but it's just making up for the wrong saddle position.

The OP would be wise to see a knowledgeable fitter. Here's a link to someone who knows what he's doing.

https://www.stevehoggbikefitting.com...or-road-bikes/

Keep in mind that reach can only be compared properly at ONE stack height. If you're comparing two frames that have a 20mm difference in stack, then reduce the reach of the smaller frame by 6mm, assuming that 20mm of spacer would be used to create the same stack on both frames. When a big stack of spacers are used, you're reducing both the drop and the reach to the bars.

Reach is measured from the BB and for good reason.

That sounds about right to me, but I'm curious how you came to 6mm specifically.

Trigonometry.

Thanks. It all makes sense now.

Alright, I got off my lazy @#$ and did some math. It ranges from 5.5 to 6.2 from 74 to 72 degree STA, so 6mm is a good rule of thumb.

Fit the saddle and bar position for how you want to ride (upright vs stretched out)....not the other way around.

So I had a proper fitting this weekend, and he noted the seat post has a 20mm setback. I didn't realize this. He suggested getting a 0 setback post to get my knee more above the pedals, and that it would have the added benefit of reducing reach, but for now we just moved the saddle forward 15 until I get a new one. The 80mm stem surprisingly felt better than 70mm. The 90mm the bike came with is just a bit too long for the more upright/touring position I want to ride in. I'm going to take it for a 20 mile spin today and see how it does, then build up distance in this new position over the coming weeks. Going to go to my local bike shop and try their saddle testing program, too, because mine is 14cm, and my sit bones are 14.5cm. So ideally I think I'd want a 15cm saddle. Maybe some light at the end of the tunnel. We will see!

Fort,
Not sure how much you've been riding, but here's my recent experience with bike fit; re-started riding six months ago after retiring, and totally required an upright position.

After 6 months of riding 5-7 hrs a week, my flexibility improved so much my comfort position changed significantly. So keep all your old parts 😉.

Haha. I will keep that in mind.
I've biked about 800 miles this winter. Just 25 mile maintenance rides to stay in shape. Usually at least 2 rides per week.

Excellent.