A local builder out here has been using PL construction glue for many years with great success, he makes the hull then lays down a bead of PL along the lines. he set the stringers down into the PL and has jigs to hold them in place, he like George uses a tongue depressor to form the fillet. The next day he removes the jigs and lays his glass. Which ever way you decide to go remember one important thing, isolate your stringer wood from your transom wood.
Quite a few of use have done extensive hull work, most all transoms go bad from the bottom up. IMO from poor drain plug installation, the water migrates from the transom wood into the stringers and then seeps forward. My structural work was done by the head glass guy from Hustler, my rot was very similar to yours. Bottom 1/3 of the transom black and rotting and about 4 feet of the stringers were wet with only about 8-10 inches rotting aft. He kept cutting the stringers advancing forward until dry dust came out of the cuts, ended up about 6 feet he capped off the old stringer ends with glass. He then made up doubled replacement stringers which overlapped screwed with glass and resin between to the originals, I ended up with doubled stringers fro the fuel tank aft. He also added two additional bulk heads and four new gussets, he said it would handle a very powerful big block with no sweat. Doubt I will break any of it with my mouse motor!
No matter what your beliefs are "GOD BLESS AMERICA"
Fully retired marine tech near 60 years in the biz.