Upon further experimentation, launcher into ground chain might not be as good as previously thought for some characters. It appears that if at any point your ground chain causes them to land, it's not actually a true combo anymore, you can tell by the fact that you can launch them again. I've never actually seen the AI block or punish this, so right now you can just abuse this anyway by looping it indefinitely, but it's something to keep in mind if you're trying to craft real combos.
AFAIK here's as far as it can actually work as a true combo:
Peacock: launch, ground 12 (Have to catch them fairly early to get the second hit without them landing.)
Painwheel: launch, ground 1 (Yup, that's all you can really get. As if poor PW didn't have it hard enough.)
Band: launch, ground 123, SSJ (Timing is strict but it can work.)
Filia: launch, ground 123, sweep, Drill Tempered (This is damn good! Tack forward, ground 123 onto the beginning and you'll build a full bar in time for the super. I assume Gregor should work too.)
Bella, Val: Can't seem to catch anyone in the air at all.
Going back to air chains and what you can do with those, found that in the corner Bella forwardx2 can actually OTG some of the cast, but unfortunately it's not universal.
forward, ground 123, launch, air 123, forwardx2, Dynamo/Diamonds are Forever (Have to be very fast. IIRC it works on Band, Bella, Painwheel, whiffs on Eliza or Parasoul. Not sure about the rest of the cast.)
forward, ground 123, Diamond Drop, forwardx2 (This one does work on Eliza on the other hand.)