1) could you allow to "Use Dynadot DNS" and specify third party NS on a domain at the same time? 2) could you allow AXFR to those 3rd party NS specified in (1)?
This should help us at times when nameservers in dynadot domain are attacked.
So far, when I specify dynadot nameservers manually instead of clicking "Use Dynadot DNS" on DNS tab they stop responding to requests for my domain.
I know that. This seems to be a way dynadot's system is implemented and I am asking you to change that. If you do, nobody will have a right to complain if their sites were down when you were attacked.
Nothing technically prevents dynadot to continue serving "Dynadot DNS" when both Dynadot and non-Dynadot servers are listed on the domain. Moreover, if you allow AXFR from your servers, the non-Dynadot servers could be pure secondary slaves (like xpertdns 5-domain slave plan for $7/yr, I am not affiliated), without the need to laboriously copy all settings.