I’m fixing up my garage, looking for some insulation guidance. The framing was done by somebody’s grandfather in the 40’s and it’s real crazy, but then, it’s stood there in southern CA earthquakes for about 70 years so I’m not too worried about it. Anyway, I’d like to attach T & G or drywall directly to the roof rafters, to keep the vaulted look but can’t figure out how best to insulate it since there’d be no attic.

idea #1: put Dow Tuff-R rigid insulation in between the rafters, fill in gaps with Great Stuff foam.
idea #2: if I go with T & G, drop in Green Fiber Insulation as I work my way up.
idea #3: somebody told me there’s a Thermax board that’s white and attractive looking that could be attached directly to the rafters and would look as nice as painted drywall and provide adequate insulation.
idea #4: spray foam
idea #5: ??

The spacing for the rafters is all over the place so batt insulation probably isn’t an option? (Plus I keep hearing fiberglass sucks?)

See attached image.

Thanks in advance for any advice!