The old way actually works perfectly (any of my recent freebies) - which is funny because that's not actually a supported feature and never really was.  The new way is what seems to be bugged, it doesn't look like it works at all.  I tried this with a garment set up from scratch with morphs that were never set up to be controlled by ERC, the new checkbox feature applies whatever morph twice - if you go back to the garment and dial it to -1 it looks correct.  It's just plain bugged.

My Freebies