As of this writing, I do not.
Boat was not wired that way when I got it.
I understand the concept though. If the oil pressure drops, it cuts off the fuel flow.
I specifically bought a very low pressure pump so it wouldn't overfill the carb with the engine not running.
I've even gone so far as to run the pump with the engine off, watching the carb throat to see if any fuel would leak out. Verified the carb installed has a valid and in good shape needle valve seal.
It does not leak fuel with pump running and engine off currently.
That doesn't mean it never will however.
The oil pressure switch is just the standard can type single contact switch
connected to a variable pressure gauge.
Would you need a different type of sending unit to do this?
This is whats installed currently.