With the lower resolution the FPS could be a bit higher but it depends on how you setup the graphics. Competitively lowering the "extra flashy" stuff and keeping view distance far is ideal and with those parts I would think 144hz should be fairly easy but it's something you may need to tweak until you find that good graphics to performance mix.
It's a shame with all of this Covid stuff going on you can't check out these monitors side by side in a store as that could help with your decision.