It seems like inbound and outbound zone transfers aren't offered by a number of providers (like AWS). Do you know of a list of DNS providers that support either option?
https://puck.nether.net/dns
https://acc.rollernet.us/
I only stopped using them because I wanted to run my own DNS service.
They have an interesting blog post about setting up secondary DNS: http://blog.easydns.org/2013/09/10/what-we-are-doing-about-c...
I have no affiliation with them, just a happy customer.
My research into it is from a "manage your DNS records internally, then use a couple of providers for all public facing responders". In that situation all you need them to support is inbound transfers, which several do.