This. I have been running it the same way for some time now. Even if you change something on one machine and something else on another nextcloud will just happily inform you of the conflict and then you can open both databases and cherry pick. Never had corruption issues.
Worked as a sysadmin for years dealing with all kinds of certificates. Liek others have said if you can’t automate the process a paid certificate buys you 12 months at a time in validity. Also wildcard certificates are more difficult to do automated with let’s encrypt. If you want EV certificates (where the cert company actually calls you up and verifies you’re the company you claim to be) you also need to go the paid route
In my experience trustworthyness of certs is not an issue with LE. I sometimes check websites certs and of I see they’re LE I’m more like “Good for them”
https://youtu.be/dH4n8fUjtLQ