As an ISP you are allowed to hand out my DNS64 addresses to your customers as long as you comply with the following requirements:

You can hand out my DNS64 addresses to your customers using router-advertisements, DHCPv6, or by other means.

I cannot provide guarantees about bandwidth availability. Howeever there is a few pieces of information you can provide me in advance to improve the chances that I'll be able to accommodate your traffic:

I will share your estimates with the transit providers unless you explicitly ask me not to.

If I have to prioritize traffic due to capacity reasons the following criteria will be taken into account in guiding my decisions on who to prioritize and who to throttle:

If you wish to have DNS64 hosted on your own network you can provision an Ubuntu 18.04 machine (virtual or physical) on which I can operate a DNS64 server which will hand out addresses using my NAT64 pool.