Maybe it's an idea to create a second customer panel?
It does not matter to the server under which user the server is running. Actually it could become a very simple user panel with access to FTP, create email and so on.
To be able to run it with AApanel, write an API.
For example, there is not much to renovate existing control panel, and they are strictly separated.
(a suggestion in name: CApanel đ) Customer access panel