Nah don’t use those. Get your own direct from Let’s Encrypt. Less hoops to go through when its time to renew. Acme with a crontab entry takes care of renewals automatically. Don’t forget to add to the crontab line to restart nginx right after the renewal so that the new certs are used.
Edit: spelling
I selfhost both Lemmy and Mastodon. Lemmy is set and forget follow the communities you etc. Mastodon does need a little bit of tweeking after being setup. I have a script the removes remote content from my server after 7 days which keeps the used space down considerably. More details about the commands used can be found here -> https://docs.joinmastodon.org/admin/tootctl/#media-remove