we don't need full physics to do station things(refueling, run science gear, transper crew, ect) while docked, isn't it? and orbits should stay same while there is no engine or RCS.
so how about disable physics while there is no thruster active(engine or RCS) or turn on and off manually, we can stop float physics from affect orbit and disable physics (like whole ship as a single rigid body and allow reaction wheel to turn ships slowly.)
It's about docking large ship to a large station, and even in 1.1 multi thread support it would cause game extreamly slow while it doesn't really need full physics (you won't move station anyway while a random large ship docked.)