Noticed a comment stating that being forward on the bike was more stressful than sitting further back.
I thought it was the opposite.
Who knows?

The seatpost angle of short frames is always 74 or more degrees on the 700c bikes I ride.

Saw a statement that a rearward seat position would cause less knee strain. Is that correct?
Thought a forward seat would cause less knee strain and be better for spinning.

I've heard from more than one person that having your knee slightly behind the pedal spindle (as opposed to KOPS) helps to prevent knee stress for most people. I think that would argue for a more rearward seat position...

Bicycling magazine has an interesting blurb on cleat positioning in their October issue. Basically, forward lets you develop more power but tires your calves out quickly. Cleats moved back give your legs better endurance.

Too forward is stressful, too far back is stressful. Each person has a sweet spot. Knee Over Pedal Spindle (KOPS) is a common recomendation to start from and adjust from there.

This might be obvious, but -

If you move your seat forward without raising it as well, you will effectively have dropped it. This will add to knee stress.

dude. post once and bump.

+1

Do you currently have knee problems or are you looking to avoid potential knee problems?

Can't escape that.
Agreed there, too. There are always kneejerk rejections to the KOPS recommendation but the people who give those rejections seldom give an alternative.

Of course, the most simple thing is to let the fitter decide.

That's about cleat position, not seat position.

I've tried different positions, for me sitting more backward produces less knee stress...but also less power.

IMO, knee strain is caused by poor cleat positioning and not spinning fast enough.
sitting further back on the saddle puts less weight on your arms.
sliding your cleats behind the ball of the foot will prevent hot spots on longer distances.

the Q-factor and proper toe-in/out, as well as properly training your leg muscle sets will prevent strain. you should aim for a balanced leg muscle set. if one set is stronger than the other, it causes your leg to twist, which leads to injury.
if your bones make your regular stance toe-in or out, the cleat should be rotated accordingly.

Saddle-height contributes way more to knee problems than fore-aft adjustments. You can slide the saddle forward & backwards +/- 10mm without too much problem. But try that with saddle-height and you'll be in the pain-zone immediately.

I don't have a knee stress measuring device. Does anyone? How could you possibly know what's going on inside your knee joint with slightly altered saddle positions? I say that most responses are pure conjecture.

FWIW, I've tried everything from 1cm forward to 3cm back (of KOP). I do a lot of climbing and feel that 1-2cm back works best for me, but the larger benefit is reduced weight on your hands and the ability to comfortably tolerate a larger saddle to bar drop. I don't even bother to check KOP these days, since I feel that weight balance is more important. Even the experts don't agree on how to check KOP. Andy Pruitt uses the very front of the knee to the end of the crankarm, while others say to use the lower boney protrusion to the pedal spindle.

A lot of posters on this forum make the mistake of using a nonsetback post that places too much weight on the hands. Then they use a short stem and little saddle to bar drop to cure the discomfort created by the first mistake. The result is an upright Fred fit.

Helped me tremendously, I also recommend starting here.