I’d set a hard limit of a minimum of 2 other posts in between your own. I don’t think we should be doing calculations like 1/2 or 1/5 or whatever. Two posts from other players ought to be enough.
The moderation should be left to you, as the GM. The rest of us will try to use our common sense not to do it.
I’d stick with floating, and using “mag boots” only when you need stability. It would be good if they had an on/off switch.