Ok, yes, writing the stop changes on the pedal staff does indeed work.
One tweak I found nessesary was in the Playback Option Overrdies to reduce the Legato Duration to something under 100%. Else if you have two successive notes of the same pitch under a slur essentially only get the first note - the note isn’t rearticualted, since it’s already held down, but then is abruptly cut off slightly after the 2nd note starts, as the note off from the first note fires. I find a value of 98% seems to work ok.