Summary up front:

We have the nuts, like top set oop. We bet bet and river binks a card we don't wanna see, like straight or flush card. 

What's the vaccuum play vs unknown on let's say Zoom PLO100 or so. 

My standard is to XF and balance that with some XC with rivered low/mid flushes or XR with rivered NutFlush when the board is so that Villain could bet some other missed Draws. 

The problem I have is that they often xback lower Flushes when I have the NutFlush and always bet when I check with a set :(

So basically please someone of the Pros tell me how the f...to balance correctly in this very frequent spot. 

Would it be a better balance play to always 1/3 the river in those spots to A) induce with bet/calling hands and B) to bet/fold with like top sets?

Anyone knows what I mean?