To not possible to undo any changes is the key feature I’m looking for.
Drawing apps are typically created for iPad, but for reasons that I don’t think are interesting to listen about, I need this app to work on Mac as well.
Tis unlikely that you will find an app that fits this need.
Most people cannot resist the undo.
The software you choose may not be the matter here.
The question is: can you resist the undo?