Automatyczne dodawanie domeny do strefy zapasowej na drugim zapasowym serwerze dns.

My question is directed to the creators, and by the way congratulations!
I've been using the Ispconfig system to organize my domains for many years. I use the Multiserver option, have all my own system components, and have three address pools. Everything works fine, and if it doesn't work, I always find a solution on the mailing list.
In my system, I use three DNS servers in three different address zones, and three mail servers in a similar manner. All under the control of a single Ispconfig system and a single Proxmox virtualization system in three different locations.
I am an amateur and self-taught person and I decided to ask you about the problem of automating entries in DNS servers that bothers me.
I try to help myself with additional scripts that copy zones to second servers, but it is semi-automatic and does not always work correctly.
If we have a perfectly working form for creating a DNS zone for a new domain and can select two DNS servers: ns1 and ns2. (Why not extra ns3? That's a different question.)
I'm assuming these are the primary and secondary servers. And we can define their IP addresses and names – great. And we have two physical or virtual DNS servers in a multiserver system, why can't we automatically add the same domain to the secondary zone on the second DNS server when adding a new domain to the primary DNS server?
As everyone probably knows, using the MIROR function for a second DNS server always generates several errors for a minute because the zone on the second server isn't updated yet.
Furthermore, enabling the MIROR function blocks the use of other services on that server.
Why, for example, couldn't a secondary DNS be a secondary MX? I'll leave this question and the logic of filtering mail and storing it on a backup server when the primary mail server is unreachable for another thread.
I'm very curious to hear your thoughts on how you handle this. Manually rewriting 150 domains to a backup DNS server and updating them isn't a viable approach for the 21st century.
Best regards.