Come to set-up dynamic IP for NextDNS IP sink holing for a client and read that RouterOS handles this requirement via a script. I assume that this is because the various DDNS services like No-IP implement different protocols and supporting them out of the box would be a hassle?
A bit of a non-problem with NextDNS as it also supports fetching a web page as a way to update the public IP. That's a nice "out of the box" thinking solution. So a quick scheduled script to do a /tool fetch https://xyz works treat.