I took the needle and seat out and cleaned them again. Both look good with the little rubber tip intact and free of debris. Float is set to 1/4". Got a fuel gauge and checked my fuel pressure, and it's 6psi.
Clean isn't everything. It's possible for it to leak for many reasons. I'd either replace the needle/seat proactively, or attach a hose to the fuel inlet and fill the hose with gas while holding the needle into the seat (lightly), and see if the needle/seat leaks at all - even if it doesn't leak at rest, it may leak under pressure still. I've done this with lots of small engine carbs and 10/10 the needle leaks and has been my issue.
