So glad it’s finally working! 
About:
According to https://letsencrypt.org/docs/duplicate-certificate-limit/#description, It seems to me that it’s five times a sliding week.
It is displayed by https://gitlab.e.foundation/e/infra/ecloud-selfhosting/-/blob/master/scripts/postinstall.sh?ref_type=heads#L166.
For next release, I’ll ask this to be added to install guide, replacing the obsolete Rainloop part 
Once proven working, you may activate SQL backups as described here: https://gitlab.e.foundation/e/infra/ecloud-selfhosting/-/blob/master/docs/SQL_backups.md.
just saw there is a typo in first line, files to be checked/modified are /mnt/repo-base/scripts/mariadb-nc-backup.sh and /mnt/repo-base/scripts/mariadb-pf-backup.sh (will also get that corrected for next release).
As a side note : this will only backup SQL databases to plain (compressed) files, for files backup you’ll have to rely on your hoster or a third-party solution (choose the backup time windows after the SQL backups).
I also wrote some words about securing your server with CrowdSec.