I think the LM317 was suggested to me when trying to use a voltage regulator was pointed out to be the wrong apporach.. and I needed to regulate the current
Looking at the LM317 datasheet.. I mirrored the current regulating schematic.
as far as the other stuff.. (if it even fits the current project size..etc.. I dont believe a buck puck even applies here?) is not something I intentionally snubbed.. I just didnt/dont know any better yet.
as mentioned it was my first attempt at a constant current anything.. LOL