Unfortunately it means you're off the happy path in terms of certificate renewals. Most (?) hosting providers these days probably provide for automated renewal

Unfortunately it means you're off the happy path in terms of certificate renewals. Most (?) hosting providers these days probably provide for automated renewal of individual domains, but wildcard certificates are a different matter, especially if your domains are hosted/registered externally and you're not using your hosting providers DNS servers. If you're lucky and your hosting provider is using e.g. Plesk as a hosting panel and has enabled its built-in DNS server, you might be able to use that as a (hidden) primary server and your registrar's DNS as secondaries and let Plesk update the DNS records as required. Otherwise you're left with the problem on how to interface between your hosting providers renewal mechanism and your DNS provider's API (hopefully your DNS provider does have an API?), which means you either need to manually update your certificates after all, or else run your own webserver so you can custom-wire the required DNS updates (and running my own webserver isn't a hobby I currently wish to take up).