mdma and play, the safety stuff nobody mentions

right disclaimer first, im not asking how to take it or where to get it, im asking honest experience questions for people who already do this. mdma has come up a couple of times at private parties weve been to, never pressured, always offered, weve declined so far. we're tempted at some point but the bits that worry me arent the play bits, theyre the practical safety things, hydration, dosing, mixing with anything else, comedown the next day, jaw stuff, what happens to consent capacity, what to do if one of us is having a bad time mid night. these are conversations that just dont seem to happen openly. if youve been there, what do you wish someone had told you before...