Update here for anyone the thread might help in the future:
I found Super basic Z-Wave parameter tool (Thank you, @mike.maxwell!) and set the switch ramp rates to 1 second. They appear to report their level 1 second into the change, so this results in them reporting 99% as they should, instead of 39% during a 3 second ramp. Now ML sees the level where it's expected and functions perfectly.
It looks like in later WD200+ firmware, the switch will report both its current level and its target level. The upgrade story is miserable, between the newer ZWave version running them out of space for code and the user needing a paid license and hardware for the upgrade software; so I doubt I'll ever get there, but it could be a helpful feature in the future.
Saw the "physical" option appeared in the latest HE release too, so I'll play around with that. Thank you, @bravenel!
