I thought someone like you might know this.... but a light bullet recoils less... a heavy bullet recoils more.....Shoot to learn, or shoot to compete?
If you want to win much in F Open, it's going to take a 6.5-284 or 7mm of some type, though you might pull it off with Dasher or 6mm derivative if you shoot where the wind doesn't blow much.
If you want to learn, and learn wind calls, you can do it much cheaper with a .308 and shoot in FT/R.
It's much cheaper to shoot, there is lots of match quality ammo available, as well as match brass. You can jump in easy with a Savage factory rifle, and they shoot well enough that the US F class team was mostly the Savage factory shooters! A decent .308 barrel will probably go 3-5000 rounds, easily 3 times what the 7mm and 6.5-284's will do.
I'm addicted, and I don't find that shooting 60-100 rounds of 7mm WSM causes me any problems on day two of shooting, but some people do evidently. If you shoot a rifle in the higher legal weights, it just doesn't seem to be much problem. Shoot an 8 pounder for 60 shots, I bet it would beat you up. Shoot an 18 pounder, not so much.
Of course, I'm just a shooter, not a national level guy, so take anything I say with a grain of salt!!