Belgian Triple In Keg , How long till drinkable ?

I recently transferred my Belgian Triple into a keg after 4 weeks fermenting . It is now in my kegerator @40f with 12psi on it. my question is how long should i let it sit before it will be most enjoyable ? should I pressurize the keg @ 30psi and take it off gas and pull it from the fridge and let it sit for some time? or should i leave it in the fridge ( consuming valuable space ) till its ready?

Leave it hooked up to serving pressure.

There really is no good answer that someone here can give you about when it will be ready because it all comes down to variables that we have no way of knowing. If you pitched the proper amount of healthy and happy yeast, and kept them happy temperature wise, there is no reason why your beer would take any longer than another. A tripel is a good style to drink a lot earlier than a quad, it has a lot of brightness that is wonderful when fresh.