Hi,
This page mentions only how to rollback a whole upgrade.
https://getsol.us/articles/package-management/history-and-rollback/en/
I know that can lead to issues to have one package not in sync with the others.
It's for Thunderbird, to support an extension that hasn't yet been ported to version 68 (same context as the switch to WebExtention only in Firefox, few versions ago)
If Thunderbird starts to crash, I'll update it anyway and do without the extension.
nope, you have to roll back the whole update and just not update thunderbird via SC
Rollback the whole update and then update with sudo eopkg up --exclude thunderbird
In my case since this update I had 2 other updates and 6 installs, so I have to rollback them all, right?
Yes, simply use the highest "Operation" number before the Thunderbird update in your rollback command.
Staudey This information is to me very valuable. Currently with my OBS, its not outputting the "Monitor & Output" sounds at all to my headphones, or to the Audience. The Ability to perform a rollback with this specific exclusion would be great in the help section in case a user not very technically inclined such as myself, needs to perform this. 
