As you know... Things change as ya go along.

If I saw the bike set up I am ridding now thirty years ago I would certainly laugh. One thing I have learned is not to make big changes. So if ya end up going to the hack saw make it little, itty, bitty, cuts...

So I recently built a MTB (fits into the downcountry slot) and wasn't sure about size. It was my first proper MTB so didn't have experience to rely on, picked a large frame based on other's heights & inseams, and what they thought of their fit. When I built the bike up the distance from bars to saddle seemed ridiulously small. I thought I'd made a big mistake. After riding it a bit and making little tweaks to stem and types of handle bar the bike feels soooo good. It wasn't until later, going down the youtube rabbit hole, that I came across the RAD fit method. For curiosity I measured it up and turns out the RAD is pretty much bang on (IIRC within 1cm). I know it's only a sample size of one, but seems there's something to it.

Interesting formula. Puts my max width at just about 800mm. Just did a ride on 800mm bars today and I am now convinced that it's too wide. Tempted to chop 25 mm from each end before the next ride to see how it feels.

Most of my MTBs have a 13cm stem and bars ranging from 55 to 65cm. 4 of my mountain bikes have a hi riser bar and 3 others have flat bars. My two other mountain bike projects are going to again include a 13cm stem and 60 to 65cm hi riser bar. I always used this set up for my mountain bikes and never had any back or arms aches or issues.