On flush draws one-carded and third-nut

I play it exactly the same.
A value bet on the end HU I can see (both if I have no flush [better hands will fold] and if I have Q+ [worse hands will call]) but into 2 villians I don't.
Betting into 2 villians, I'm guessing only T,J,K,A flushes are playing. You win 1BB from T and J but you're probably losing 2BB to both K and A.