Mouse input stutters / jitters independent of framerate, controller fine

I hardly feel this when Frame Generation is enabled, but with it on, the input lag is terrible. Turning it off, however, gives me this horrible jittering. I hope they fix it—preferably before the second weekend of the open beta. For me, it’ll make a difference whether I buy it now or wait until they report it as fixed. In its current state, it’s such an annoyance that I didn’t even play on Sunday.