Okay so my first boil which had about 1 litre of water, 76g B. Caapi (yellow), and 1tsp vinegar was pretty thick, I then filtered with a cheesecloth folded twice over itself, I then rinsed off the cheesecloth with the distilled water I was using for the next boil.... well now it's not nearly as thick. I'm worried it wasn't filtered well enough, but I have read elsewhere that cheesecloth works perfectly fine. Any information would be great, I worry after this second boil, that where wont be any sediment to boil a third time, meaning it all dissolved into the tea. Also, this is powdered caapi, so maybe this is expected. I've tried searching around with no avail.

That cloth is not good in filtering powder as you noticed. Textile filtering is good for shredded or pieces. The only way I see with powder is to let it settle overnight and skim off the top layer.

The good news is that powder caapi needs very little boiling. You might be surprised how powerful a 15 minutes boil is, just once. That is the bare minimum though.
It's mentioned that prolonged boiling leads to more THH, this would be a reason to boil for many hours.

The one powder might be finer than the other powder though.