I don’t know what other’s workflow looks like but sometimes when working I will often lock a layer to not select it, but yet I have that geometry is a guide or reference.
At some point in modelling I need to zoom in an do some precise work, so I just type Isolate.
Often, I would say always, I also need the reference geometry to go away.
All times I use isolate I only want selected object to be visible. To control this visibility so indirectly as with locked layers does not feel right.
I am willing to have some common ground and suggest only manually locked objects get included in isolate. But layer locked objects should go…