You can also become a registrar yourself - at least, RIPE allows it. However, fees are significantly higher and it's not clear why you'd want to, unless you were actually providing ISP services to customers (in which case it's mandatory - you're not allowed to use a PI allocation for that)

> and it's not clear why you'd want to

The biggest modern-era reason is direct access to update your RPKI entries.

But this only matters if you are doing stuff that makes direct access worthwhile.

If your setup is mostly "set and forget" then you should just accept the lag associated with needing to open a ticket with your sponsor to update the RPKI.