For starters, the only way of enabling a plugin now is by doing a full rebuild, so that is a killer here. We would need to build a system that allows you to enable/disable plugins from /admin which requires a whole bunch of work.
I think the first task here regardless is “enable / disable” buttons in /admin/upgrade that knows to talk to the server and restart it. (note, none of this work is really reusable for our internal hosting something that makes me not super enthused about doing it now)