I currently use directadmin for hosting websites and email. The DNS entries are hosted on DA as well. Would there be an issue with hosting the DNS with an outside service but still having DA do the websites and email? Any gotchas?
I use and require lets encrypt but not wild cards. Would that be a problem?
I have lots internet access to my Directadmin server a few times due to a fiber cut. I would like to have the DNS hosting done in cloud so it remains active in that event and a few extra features the cloud service offers I would like.
You might best use the way k1l0b1t is using it, this way you can do anything you want.
If you are keep using purely external DNS, you have to take in mind you can not use wildcards. That is not a problem I see.
However, you also have to manually copy over SPF an DKIM records if you use them, and I would advise to at least use SPF. Same for DMARC if used.
Also if you change A records, you have to manually put them in the external DNS also.
If that is not an issue, it's no problem to use purely external DNS.