I’m using just one right now (OSID), although I’ve often used two or three at a time. The issues I’ve had with multiple lists is that sometimes certain websites or other internet resources won’t open and I can’t figure out why. After spinning my wheels for a while, I finally remember to stop Blokada, which solves that access problem. Then I switch host list to see if that will still block ads but fix my specific non-access issue. So that’s why I change host lists. Also, using multiple lists will complicate potential access problems.
I don’t see any way to extend the 30-day closing of a support issue other than reposting. Good luck! Maybe someone else will chime in? (Karol?)