Different DNS adresses from different Networks

Hey, i hope this is the right community to ask questions about DNS. If not I apologize.

I have a Server behind double NAT, but with a VPN to a Colo be publicly accessible. I want to optimize access speed performance through DNS (as this is the easiest way, I can think of. If this is a stupid idea, you can also tell me)

This is my network layout: https://imgur.com/a/cLPdtTm

My DNS Server is on AWS Route 53 and on Network A I also have a DNS Server I control. Network B is not under my control, so I have to add it to my Route 53 Zone to be able to use it there.

Since the Speed between B and A is nearly Gigabit, but going over WAN is severely limited by the VPN performance, I would prefer for the traffic to go directly to Router A, when accessing the server from Network B.

Can I just add the 10.5.19.68 address next to my public 193.xxx.164.47 address in the AWS DNS? What will happen if a Client thats not on network B receives the 10. address for my server? Will the client be smart enough to realize, that the server is not there or will it try to contact the wrong server (if there is any at that address).

Can I configure the DNS Server to answer the 10. address only, if the request comes from a specific IP Space?

Thanks for your help! I hope these questions are not too stupid.
-Lemmi