Can be problematic… imagine that :
- you freeze your track.
- you move, cut, remove things.
- you unfreeze the track…
what happens ? - The unfreezed parts represent the new arrangement…
- Or they are like before edits…
If you consider to edit a track, and admitting that in certain way, a freezed track is “just” a stereo bounce, then the better is to bounce your track and make the edits with audio clip, or unfreeze make your edits, and refreeze. I think that, is the way the freeze function is build. A realtime VST could not be modified inside a freezed track, but maybe there could be an option to select which plugins are frozen on the chain… 
i don’t think so, if you just want to unfreeze the before last plugin but freeze the last one, it can be too much complex to code a thing like that.
But yes, maybe just moving and duplicating parts could be possible.