Unfortunately, I have to report back with negative opinions: none of the oscilloscopes linked above are, IMO, suitable for monitoring signals like a Mordax DATA or VCV's Scope can do, they are like most VST oscilloscopes I've tried, focused on monitoring audio waveforms specifically.
I'm reverting back to VCV, until someone finally comes along and makes a better one. If I'm desperate enough, I might pull the VCV code and see if I can make my own version that allows zooming...

--- Voltage control all the things ---