I don't mind hosting my DNS at registrar, since they provide the service, but I do want to have secondary DNS servers/provider somewhere else: dns.he.net (free)

I don't mind hosting my DNS at registrar, since they provide the service, but I do want to have secondary DNS servers/provider somewhere else: dns.he.net (free), or paid service elsewhere. But, unfortunately, none of the registrars I tried allow you to have secondary DNS server, ie allow dns AXFR for the zone file. (godaddy, hover, gandi, namecheap and 1and1 -- note, I tried them over the time and asked all of them for AXFR to have secondary zone elsewhere -- all of them declined. Latest and current is Hover). After long time researching, I've decided to use $2/month plan on cloudns.net for primary DNS, and secondary at dns.he.net.