I made a plum bow recently from a branch 3.5 cm in diameter, with recurves, 155 cm (61"), c. 50# at 28". Since it's obviously quite crowned on the back, I didn't want to heat treat the belly.
To avoid checking during curing, I cut a shallow kerf with a table saw 1 cm or so along its entire length, and that's where it checked further over its entire length, opening itself for 1.5 cm. A few months later, I cut it entirely in two with a table saw, and turned one half into a bow. Recurved the tips with steam (4 cm or so). Had to glue a handle to it and still keep the handle working without it popping off. That was the hardest part...
The bow is a dream, taking virtually no set. Maybe 0.5 cm after shooting, returning to straight within minutes.
I've made a few other plum sapling/branch bows in the past. Superb wood if you ask me, strong in compression. but mind pins on top of the crowns, or laterally on the belly. I once had an explosive break of a heavily crowned plum shorty (50" drawn to 26"), where I suspect a lateral pin at the surface of the belly weakened the belly to the point that the neutral plane suddenly moved towards the back of the bow, leading to a bow breaking as a result of a compression failure.