"...Saw something the other day on Wild Tv. Stan Potts of North American Whitetail uses a slow set glew for the inserts and rotates the broadhead until the blades are in line with the flethchings. Then he spins them for a final check..."
Yes. I do the same, minus the spin test as I don't have a spinner.
"...Been told the same about heating the ends of the arrow shafts/inserts and rotating the broadheads until the blades line up with the fletchings. Fine for aluminum arrows but not sure about carbon shafts..."
Yes...that used to work great on aluminums...but not so much on carbon arrows. Tried last year, and tried very hard LOL with no luck. Tech at the archery shop said the glue is a little different now for carbons, virtually impossible to move once it sets.
So now I get my arrows cut to the length I want, then pick 6 "hunting only" arrows ( 3 for my G5 broadheads and 3 for my practice G5 broadheads )...screw the broadhead into the insert, THEN put the insert in with glue on it and rotate it to where I want it ( I still believe in lining up the 3 blade broadhead with the 3 fletchings).