Transfer domains ASAP, there are 2800+ icaan registrars, I use gkg.net. Fill the complain to icaan about cloudflare. A civil case is also possible.

And host your DNS using multiple cheap vms using multiple companies + power DNS.

If you don't want to manage this yourself, use at least two companies DNS auth services and edit their apex NS list accordingly, ignore SOA being different, and make sure you changes are applied to both DNS providers.

And keep your (A)dress/(AAAA)ddress records TTL low, max 3 hours so you can act quickly.

I've used cloudns.net and digital ocean both for one domain, both allows to edit NS in apex.