For a multiserver setup, it looks to me I can use ISPConfig Autoinstaller (from git.ispconfig.org) to install the master server. But then for the slave servers I have to install following the Perfect Server Guide and ISPConfig Manual to get the install done in Expert mode. Is this correct?
I am currently writing a guide on this that will probably released within a few days - do you want to test it? I can send you the draft.
You can force the auto-installer to start the ISPConfig installation part in interactive mode, which then allows you to select expert mode in the ISPConfig installer. Code: curl https://get.ispconfig.org | sh -s -- --interactive But there might be other things to obey, so waiting for Thom's new multiserver install guide is probably not a bad idea