Hello,
We've been having this issue for years now. Whenever we use a Mac with a mouse that polls often (i.e. 1KHz), Remote Desktop for Mac becomes painfully slow to use.
Our workaround is to use our Magic Trackpad, or built-in trackpad if on a laptop.
I followed the support link in the Mac App Store and was led here - so this is where I'm filing the bug report. If anyone knows a better place, please speak up.
Thanks!