I had a disaster with hot glue and t-molding on a Robotron restoration. Hard to explain, but.. Imagine that you could just evenly seat the t-molding where it won't hold in well, but in places were the slot is tight, you can pound it in a bit farther so it seats flatter..
The slot was blown out in places from the old t-molding being removed. I tried to put some t-molding in, apply some hot glue, etc..and it was an uneven mess. Add to that the heat from the glue distorted the molding. I ended up digging all of that back out..and digging the rubbery glue out of the groove is the worst... then gluing strips of wood into the groove, flush cut those protruding strips with a flush cut bit, then recut with a 1/16" slot cutting bit.
Sounds like a lot of work, but wish I'd just filled the old slot and recut in the first place. Some may have passable results gluing the t-molding in, but my experience was that it ends up uneven and not 'flat' against the panel edge.