Similar to Drift, where I used DNS TXT records to gauge my potential 3rd party blast radius, I have scanned 1300 tech domains for the common Gainsight DNS CNAME records gsemail or gsnemail.
230 domains have one or both of these entries.
It doesn't mean they were breached, use Gainsight, or weren't affected (different domain). But I like to have an idea of who I might be talking to soon.