Does this help put the dock on multiple monitors permanently? I hate current macOS with its single dock on 1 monitor that changes randomly.
Moving the mouse pointer to middle of bottom edge of a screen will permanently move the Dock there. As far as I know, there is no way to disable this behavior. It's terrible.
For simultaneous multi-monitor, you're probably forced into using a full Dock replacement. There are a few options out there, but none have ever stuck with me personally.
I'm not a Spaces user so not sure what impact this has outside of the dock behaviour.