I'm sorry for late answer. I kinda disappeared after a hurray moment. I'm more active on my alt account, but I will take this a bit more seriously now.
To answer the question:
sourcing discussion is location specific - vendors in EU are of no interest for people outside of EU and it's just useless posts
sourcing is necessarily full of shilling, repetitive posts, hate posts. Just general low quality.
I just created https://lemmy.world/c/kratomeu for sourcing discussions in the EU. The idea is that the "kratom" community will be rather general topics and therefore higher quality, while kratomeu will be for inherently lower quality (but perhaps still useful) discussion on the sourcing within EU. I encourage somebody to create communities for sourcing within USA and elsewhere ...