this is for blendshape sculptors mainly, but I guess others could benefit from it too. it would go hand in hand with one of my previous suggestions ( group visibility )
the idea here is that when someone is testing the shapes with the visibility slider, it can only preview that specific layer, and if changes were made on lower subdiv levels ( which makes sense most of the time with blendshapes ), one has to export out everything as an obj, turn off every sculpt layer on every subdiv level, then go to top subdiv level, import back the geo as a sculpt layer, and test it with the visibility slider. even writing down this workflow is a pain.
suggestion of course is the ability to convert layers from lower subdiv levels to higher ones (and group visibility). merging selected layers on all subdiv levels into one sculpt layer could work as well, but it would be less ideal.
