There are some alternatives, such as requiring connecting a keyboard to access the command-line interface to enter commands for sideloading (you can then discon

There are some alternatives, such as requiring connecting a keyboard to access the command-line interface to enter commands for sideloading (you can then disconnect the keyboard afterward, and the software will continue to work unless it is software that requires a keyboard). An account should not be required to do this. (I think that it could also include the note that some kinds of settings by the hidden command-line interface will void the warranty.) User-defined sandbox filtering is also a good idea, and this is independent of sideloading. (The user can also disable this feature if they do not want it. However, it should have a stealth mode that the user can configure; this is needed in order to avoid abuse.) The other consideration might be to avoid someone to change something and then give it to someone else who is unaware of such changes; it is unclear how to deal with this, but it is possible even without sideloading by building a counterfeit device, or in many other ways too that do not require sideloading (including by security holes, by lying, and by many other things).