Ayyy, hopefully the mouse input gets fixed up. I can't really play it right now because of how floaty it feels for me.
For now, two things you can/should try (if you haven't already) - disable uncapped framerate and try turning off v-sync. We're aware that uncapped seems to be adding a slight amount of input delay and I've seen some other players online say that disabling v-sync made it feel much more responsive for them.