pentode as a triode

From looking at tube microphone schematics I have noted that pentodes used as a triode in the circuit have the G3 connected to the cathode or connected to the plate and G2.

Some pentodes have G3 wired to the cathode in the tube

From page 36 in the Radiotron 4th edition, suppressor to cathode CAN have lower noise if there is a leakage path between them

Suppressor to plate CAN have lower noise if there is a leakage path between them.

My question is how do you find out what connection should be the best if the tube is a true pentode?

U47,C800G G2,G3 connected to plate. U67,VM1 G3 to cathode.

That is a good question. I don't have a good answer on how to do it other that hook it up and listen. It may depend on the overall circuit the tube is used in. I have noticed 6AU6 mostly use plate connection and EF86 mostly cathode. Unfortunately, I have done nothing but wonder about it myself.

Look at this, the fist mag I pick up, the first article has not one, but two tubes hooked up that way:
They say it sounded better. Just do an a/b test. Most tubes have the supressor connected internally so you can't do this trick.

bump