Frankenstein Bassman relay switchng question

[Fiat_cc]

Hi all.
Been working on this for a client. It's a mashup of about 4 different Bassman models, and each channel with a boost.  The bass channel is mainly AA864 and AB165, and the guitar channel is based on the 6G6-A, with a Bassman 100/Fender Twin style output section. It will be used for both bass and guitar, and the owner was keen to be able to get it dirty on both channels.

Short of any glaring errors, I'm reasonably happy with the overall concept, but I was hoping to get a bit of help with the relay switching, to minimise pop. Whist there are no capacitors directly either side of the switching options, it does strike me that the grid reference to ground will change very quickly, and thus the bias of the tube may take a moment to settle, and this may be audible as a pop. Can anyone suggest a good way to eliminate or significantly reduce this (or tell me that in fact it won't be an issue)? The actual switching part of the design I am OK with, but I'm still getting my head around pop reduction methods.
Kind regards,
Reuben

[Tony Bones]

The obvious solution is to put a grid resistor to ground on the tube side of the relays.

[Fiat_cc]

The obvious solution is to put a grid resistor to ground on the tube side of the relays.

Yes I had though that too, but I wondered whether that grid resistor, when switched into boost mode and paralleled with the boost pot would still be an issue. I could lose the 3.3M safety resistors off the boost pits though.