For certbot, or certbot-auto, you can simply add --dry-run to the command (usually run in cron or systemd) and it should show you the appropriate (pass/fail) response.
[you can also look through the LE log files to ensure acme-v02 is being used]
So, what do we need to look for?
Can I tell from requests to https://acme-staging-v02.api.letsencrypt.org/acme/acct (in /var/log/letsencrypt/letsencrypt.log) that aCMEv2 is used?