This is exactly what I came here to ask for. You read my mind. I'd like a solution for the science mode and the Interstellar Tech Tree, we can't seem to load the custom tree in it.
Tried your update, Wave, seems to work so far. The science lab isn't falling through the launchpad anymore which is good news. Haven't tried anything else yet.
Having the same problems here. Tried to put a science lab on one of my rockets, and it just fell through the launch pad. Luckily I hadn't used many Interstellar parts since then.