Although we dont have the override yet for the client side transmission frequency, you can do this:
pog_foundationdonation=0
pog_coinagepercentage=0
healing_foundationdonation=0
healing_coinagepercentage=0
From your VMS and that will prevent it from sending a transmission.
I just added :
disablegsctransmission=1
To the next version. This will stop the wallet from sending any.
So, my assumption was the same with those "0" so I add it to my VPSs (with disablegsctransmission=1). It was looking that it's OK, but then I realized the maybe it's needed to copy newest version of wallet (with registered CPK). So I copied newest wallet to my VPSs, restart wallet, unlocked it and ...

went to bed, because it was too late.
Today after I came back from work I was badly surprised.
all of my VPSs sent default 2,5BBP GSCC

and 2 times because it was more than 12h.
So, now I'm totally without coinage

There were light in the dark with 1432, I add disableclientsidetransmission=1 to all my configs, but 2 of my VPS sent GSCC again despite of that. I don't know why. Maybe that config wast just badly saved. I edit it again and now it looks that it's working properly, but with my 0 coinage I'm out of play

But thanks for the update

I have few questions:
Is it needed to have newest version with registered CPK on VPS?
Is it needed to have it unlocked? (I'm using -headlesspassword)
I was looking with "exec testgscvote" on contracts and there is stated that last superblock was 123430, but I haven't any payment. Or am I looking at it badly?
Thanks