Neat, thank you for sending that over! I’ve made sure to share the specifics with the rest of the team as well 
(As an aside: thanks also for the link to the getdns api, which likewise looks super useful)
You might have already seen this, but after digging into this issue a bit, I can see that this fix to Android did get released after all, in version 11. I hope that this is at least slightly better news!
On the topic of additional features for fly certs, there’s been some interest from the community in BYO certs that you might find interesting, since being able to import your own certificate might be a tolerable workaround 