I got so annoyed with snapd that I finally patched the auto-update functionality to provide control via environment variable. It's ridiculous that this is what I have to personally go through in order to maintain control of when updates are applied on my own systems.
If enough people were to ever decide to get together and properly fork snapd and maintain the patched version I'd totally dedicate time to helping out.
https://gist.github.com/alyandon/97813f577fe906497495439c37d...