I would not like Command-Plus, as in most cases you want to increase the font size of the editor, not everything around it. Then it would work like a web app or an Electron app, which is not ideal for pro apps. But I think you do have some good points around the presentation mode.
I am perfectly fine with it scaling everything, it would certainly be better than the current situation.
Sometimes, especially when I'm pairing with a junior that has a smaller screen, I want to scale everything because I want them to see everything. In this case scaling the whole UI is a benefit even if it is a "pro" application.
YMMV, and having alternative but consistent scaling options (such as all text in the file editor rather than piecemeal) would be a massive step up from the chaos at the moment. As already mentioned, the best part of this feature rather than a full UI redesign is that you don't have to use it!
