No, but they are often kind of slow with updating to the latest patch version...

If I turn off Auto-update (via Galaxy) to install 10.3 myself: in your opinion when would it be "safe" (i.e. my saves don't get screwed) to turn it back on?

IMO - when you are playing another game. Wesp5 comes out with new ptaches fairly routinely and GOG, once they get around to it, follows on their end. With AU (auto update) on, it changes in the middle of the game and the old saves can't be used. Since you don't know when this will happen, it is never safe while playing VtMB.

Changelog for Update (added 11 April 2022):

- updated the version of the UP to 11.1.


Standalone installer updated: Version 1.2 (UP 10.2) ⇒ 1.2 (UP 11.1/11.0/10.2).