samba - Feb 2018 - using bind dlz is there a way to set ttl to zero?

I'm still not sure of the best option for my setup.

I have a couple test domains and the dhcp for my domains is handled by
another server that I use as a router.

I currently have it set to point to ns records at my ad dc servers so
that requests that are domain specific
get answered by the correct ad dc.

The only issues that arise are cached records when I update something.

One option would be to set the domain ttl's to zero if I can?
I'm not sure how to do that.

Another option would be to set my router's dns as secondary name
server for each of my test domains and since I am using bind dlz
I could do that relatively easily.

Any thoughts on other ways?