Hello Community, I'm not 100% sure if this is the best place to ask but I assume people who designed the ISPConfig Migration Toolkit have access to this forum as well. Here is the thing - I have servers that were originally installed as Debian 8.4 then migrated to Debian 9 (full story here) and jpcyrenne actually recommended there the automatic migration Toolkit which I bought license for. In the very old The Perfect Server - Debian 8.4 Jessie (Apache2, BIND, Dovecot, ISPConfig 3.1) the certificates are actually issued using certbot which is in the Perfect Server Automated ISPConfig 3 Installation on Debian 10 and Ubuntu 20.04 available but not recommended (as they recommend acme.sh). I plan to do a clean data migration using the Toolkit from Debian 9 to Ubuntu 20.04 - Server1 (currently running upgraded Debian 9) the data to be migrated to Server2 (running Ubuntu 20.04 using the above mentioned autoinstall) and once it's finished, the Server1 will be wiped and installed clean with the Ubuntu 20.04 autoinstall again. Then the data will be migrated back using the Toolkit from Server2 (running Ubuntu 20.04) to Server1 (now newly running Ubuntu 20.04). The issue is the How To Migrate ISPConfig 2, ISPConfig 3.x, Confixx or Plesk to ISPConfig 3.1 (single server) explicitly says that "The old and new server must use the same Let's Encrypt client. If your old server uses certbot, then ensure that the new system is using certbot too and not acme.sh." My questions are following: Q1: Is there any reason why the acme.sh is recommended over the certbot? (really just curious) Q2: How to best deal with this certificate generation tool incompatibility? Like I said the old servers are running certbot the new servers will be probably running acme.sh (as it's recommended), can we somehow choose to not migrate the certificates and just let the Server1 [after the clean autoinstall now running Ubuntu 20.04] generate new certificates using the acme.sh? What's the best approach to this? Setup self-signed certificates on Server1 prior to the two data migrations? Would it then not migrate the certificates? Something else? I don't mind if there are invalid/self-signed certificates (as I do the two data migrations Server1->Server2->Server1) on the websites for couple of hours, I just want a clean setup that is less headache in the future to migrate using the Toolkit from Ubuntu 20.04 to Ubuntu 22.04 LTS. Thank you in advance.