These issues all sound like problems with what's called "Smooth Scrolling" or "Pixel Scrolling" (depending on your OS), where the host's mouse sends very fine-grained scroll events, and either the host isn't sending this consistently, or something is going wrong in the conversion so that the guest isn't getting the same level of sensitivity applied.
You can probably work-around this by adjusting the following config options:
MacOS Hosts: mks.mouse.pixelScrollSensitivity (default value 8)
It sounds like most of the MacOS users here with issues should set:
mks.mouse.pixelScrollSensitivity=1
(Although you can to adjust to different values as needed.)
Higher values mean that it requires more host scrolls to produce a single guest-scroll.
Windows Hosts:
Depending on the precise problem, some combination of these options should help:
mks.win32.scalePartialScroll=TRUE
mks.win32.scaleScroll=TRUE
mks.win32.scrollScaleFactor=1200
Adjust the mks.win32.scrollScaleFactor as needed to increase/decrease the scaling. Higher values means that a single host-scroll will turn into more guest-scrolls.
I'd probably start with just the mks.win32.scalePartialScroll=TRUE option, and if that doesn't work, also add the mks.win32.scaleScroll=TRUE option, and then adjust the mks.win32.scrollScaleFactor from there if it seems to help, but only partially.
Linux Hosts:
I haven't seen any reports of this on Linux before, and I'm not aware of a config option that can help. To be honest, the Linux reports here sound more like mouse-movement problems rather than scroll-wheel problems, and might be due to Wayland/X11 interactions. (The fact that it went away with the "Gaming Mouse" setting ,and works in X11 mode also confirms that.) We'd have to investigate and get back to you, possibly with an option in a future version of Workstation.