I am searching for a secondary DNS service. While I can configure your server, I prefer to find a suitable service first.

The services I've found so far are either free and lacking in reliability or paid but with an overabundance of options that make the price unsuitable. For instance, dnsmadeeasy.com has a high price due to its complex functionality and limited domains.

Meanwhile, dyn.com is expensive for just one domain and has restrictions on monthly requests per domain. I need to manage around 25 domains, with the potential for more in the future.
I don't have any specific requirements, though I would like a short synchronization time, preferably within an hour, and support for NS, A, AAAA, CNAME, MX, TXT, PTR, and SRV records.

I have used freedns.afraid.org and www.rollernet.us/our-services/dns-services.html for several years without any issues.

I also continue to use ypdns.com in free mode to host my domain, and although I previously used secondary.net.ua for a long time, I believe it is unlikely to stop working anytime soon due to its long lifespan.

I have both used the free and paid versions of https://www.buddyns.com/. They offer 10 zones and 300,000 requests per month for free. Additionally, the paid version costs $3 per month and includes 10 zones with a total of 3 million requests (not per zone).

Other features include multiple geographically separated addresses, the ability to keep statistics on query geography (which I did not use), and the ability to add zones in batches.

For the past 3 years, we have been utilizing dyn.com as our DNS hosting provider.
But, their manager suggested upgrading to a Pro version from the Standard one due to our 5 million requests, which exceeds the service's capacity of 600 thousand. When I asked how this upgrade would benefit us, the manager has yet to respond for a week.