I haven't decided yet if I will include the ability to install the iPad app on Macs with Apple silicon. It would be relatively trivial to do, but the user experience wouldn't be great. The app's user interface is specifically designed for touch control, not mouse or keyboard, so the experience would feel … suboptimal, let's put it that way.
I'm not opposed to it in general, and I might enable this eventually, but it'll probably not be in the first release.
iPhone mirroring won't work. You will be able to open the app, of course, but for some reason beyond my understanding, Apple decided to block access to anything Bluetooth while an app is running through iPhone Mirroring. So you won't be able to actually control anything. I have no idea whether that's a bug or done so on purpose. I've filed a bug report with Apple, but based on past experience, I'm not very optimistic that this could change any time soon.