I don't know what you could use to block other than a firewall but then you'll be blocking the vps updates as well.
Concerning "Avast " program updates Avast have mentioned on this forum previously that only the final releases of the last two or three versions are supported, if you are not using a final release of one of those versions a forced update will be pushed.
I thank you for staying with the topic (bolded part above). On that note in regards to staying on topic, it is my understanding that WINPATROL will block updates. Maybe I'm wrong, but I've mentioned this application in my initial post but also mentioned it has way too many bells and whistles that I would not be interested in.
If in fact it will monitor for updates or shall we say "attempted involuntary changes to the system" as I think it will then this would be an example. I'm not sure, but if I recall correctly POPUP COP monitored for this kind of thing but this is a very old program that has long since not been supported and probably doesn't even work on anything past XP OS.
I would have thought there might be an application with a small footprint that would simply monitor for updates not initiated manually by the user, apparently I guess there are not, that is considering that the knowledgeably base on this widely used forum is not aware of any. Just thought I'd ask and of course I couldn't help myself as far as the temptation to explain my opinion on why there actually should not be a need for such an application if in fact software were to abide by self imposed settings provided to their users in the first place (which unfortunately opened the door to "Pandora's Box").
On a side note, it seems to me this would be an application for someone to write and provide the user community (I'm too old and to far out of touch to want to tackle it, but I'm sure there are capable programmers out there who certainly could in no time)