According to Reddit user Jimmyoneshot, Red Dead Redemption 2's PC port also ties
certain aspects of gameplay to player framerates. After what appears to be some pretty thorough testing, Jimmyoneshot found that in-game protagonist Arthur Morgan's Health and Stamina meters, as well as his weight, are drastically affected by the game's FPS.
If you run the game at 30 FPS, everything will be normal. You will lose weight just as you would in RDR2's console versions. However, if you run the game at 60 FPS, Core drain speed and weight loss will be twice as fast, meaning you'll need to eat 2x as much food as you normally would to keep things steady. At 120 FPS, your stat drain speed is reportedly quadrupled, and so on.
If that wasn't bad enough, Jimmyoneshot's fellow redditors have reported other FPS-related issues as well. While there don't seem to be any major, game-breaking physics bugs at high framerates, RDR2's mostly-cosmetic weather and day/night cycles are affected. Some users say heavy storms will roll in and out in as little as 30 seconds, which certainly isn't intentional behavior (I've played the game on console myself, and adverse weather usually lasts much longer than that).