So I decided to try OctoDNS and the setup outlined in the docs by @adhawkins
I first got my test site, distinctlyaverage.co.uk , running via a hostfile edit. Everything looks good and working as expected.
Next task was to point the domain at ns1/2.mythic-beasts.com as it is hosted elsewhere.
I then ran through the OctoDNS setup and this is where the problems started.
When the script runs it does upload something to the Mythic Beasts DNS via the APIv1. The A and AAAA records are there as well as a TXT record for spf1. There is also a second with an RFC1918 address space (172.16/16) which I have no clue where that comes from. The rest of the records are AWOL but they are in the .txt file in the config.
On top of that, after 48hrs since making the change the site is still not showing. It still works via the edited hosts file, but not live in the correct manner. So all I can assume is that the DNS is somehow not correct. Any thoughts appreciated.