I vaguely recall that for certbot, there’s something like you are doing for acme.sh (thanks for pushing this!), but I can’t find it just now. Will update this post if I find it.
That said, it eludes me why one should rotate the private key frequently. OTOH, exercising the process might be enough justification in itself …
danebot is a certbot wrapper that helps to avoid SMTP outages due to mismatched TLSA records resulting from a Let’s Encrypt automated certificate renewal.