Question about V2 on my RM4

I was thinking about the trio of tubes in the back of my RM4 and trying a few different ones again. I have swapped these around before with varying results. I know V1 is the input buffer and V3 is the phase inverter. V2 if I am not mistaken just buffers the effects loop, right? So in theory, If I am not using the effects loop (I run my Xpression between my RM4 and my power amp), it wouldn't matter what brand/quality of tube I place in V2, right? It would only have effect the tone if I were to use the loop, right?

There is no phase inverter tube in the RM4; that is only found in power amps.

Looking at the tubes from the back of the unit:

The bottom one is the input tube. Top right is the effects send, preout and return mixer. Top left is the post loop outs.

This is per an e-mail from Bruce to myself when I asked him the same questions.

Awesome answer, thanks goldsparkletop!