Getting a wildcard certificate from LE might be a better option, depending on how easy the extra bit of if plumbing is with your lab setup.
You need to use DNS based domain identification, and once you have a cert distribute it to all your services. The former can be automated using various common tools (look at https://github.com/joohoi/acme-dns, self-hosted unless you are only securing toys you don't really care about, if you self host DNS or your registrar doesn't have useful API access) or you can leave that as an every ~ten weeks manual job, the latter involves scripts to update you various services when a new certificate is available (either pushing from where you receive the certificate or picking up from elsewhere). I have a little VM that holds the couple of wildcard certificates (renewing them via DNS01 and acmedns on a separate machine so this one is impossible to see from the outside world), it pushes the new key and certificate out to other hosts (simple SSH to copy over then restart nginx/Apache/other).
Of course you may decide that the shin if your own CA is easier than setting all this up, as you can sign long lived certificates for yourself. I prefer this because I don't need to switch to something else if I decide to give friends/others access to something.
Your top level (sub)domain for the wildcard is still in the transparency logs of course, but nothing under it is.
You need to use DNS based domain identification, and once you have a cert distribute it to all your services. The former can be automated using various common tools (look at https://github.com/joohoi/acme-dns, self-hosted unless you are only securing toys you don't really care about, if you self host DNS or your registrar doesn't have useful API access) or you can leave that as an every ~ten weeks manual job, the latter involves scripts to update you various services when a new certificate is available (either pushing from where you receive the certificate or picking up from elsewhere). I have a little VM that holds the couple of wildcard certificates (renewing them via DNS01 and acmedns on a separate machine so this one is impossible to see from the outside world), it pushes the new key and certificate out to other hosts (simple SSH to copy over then restart nginx/Apache/other).
Of course you may decide that the shin if your own CA is easier than setting all this up, as you can sign long lived certificates for yourself. I prefer this because I don't need to switch to something else if I decide to give friends/others access to something.
Your top level (sub)domain for the wildcard is still in the transparency logs of course, but nothing under it is.