Used Watchtower on my Synology for a while and it worked well. No issues in that time.

Now I’ve moved to a Nuc and am more experienced with Docker and understand a lot more of it but by no means am a professional by any means, I would say that I wouldn’t use Watchtower. I can definitely see it messing a config up and prefer not to deal with the headache of troubleshooting something without knowing it was an auto update. If I had the time, I may tag the apps I’m happy to auto-update but for now I prefer to have the higher availability.