Several other major CAs including DigiCert do DNSSEC validation but I haven't used them and so can't even tell you from my own experience how well they work, though it seems likely some of their other customers might have noticed on that end.
Now, are they all doing a "good job"? If you actually were paying any attention at all in this space you'd presumably have quoted my already published opinions about that. I think they should retain the DNS responses the same way they would keep the actual raw data from an HTTP validation. So third parties doing incident investigation can do an effective post mortem - I also think they use too many "short cuts" that are going to result in someone finding a nasty bug one of these days and for which there's no real evidence they're necessary.
But since it seems for you a "good job" is just using something operationally, then yeah, in that limited Thomas Ptacek sense of "good job" they're already doing a good job I guess.
(Obviously, just to point something out for the thread that you already know, the vast, overwhelming majority of LetsEncrypt issuances are for zones without DNSSEC signatures).
> I haven't used them and so can't even tell you from my own experience how well they work
... I'm not sure what my "confirmation" would tell you, beyond that I know how to read the paperwork from the CAs. But sure, both Sectigo and DigiCert say their systems should deny issuance on DNSSEC failure.
CA/B Baseline Requirement 3.2.2.8 says to do RFC 6844, and that CAs need to implement at least enough DNSSEC so that they can determine whether "the domain's zone does not have a DNSSEC validation chain to the ICANN root" because if there is no DNSSEC validation chain you can treat DNS failure as permission.
In practice most larger CAs just do DNSSEC entirely here, Let's Encrypt uses it everywhere. Deployability to ordinary end user clients remains poor due to middle boxes and local DNS implementations that are garbage, but if you actually control your network (as a competent CA should) then it isn't a problem.
The sort of CAs and CA-customer relationships where DNSSEC was argued to be problematic aren't going to be doing ACME CAA, or probably ACME at all.
[Edited to delete me confusing one ID for another]