It looks like you're one of the people very involved with hunter. This also looks very interesting, since it's implemented as a set of cmake scripts, which I can just add to my module path... What's the advantage of using hunter vs ExternalProject?
I'll try to dig through the documentation later this weekend.
Since my work project is spread across so many repos, and is so complicated and my OSS time is so limited, even hacking together a prototype can be a decent time investment, so I'd appreciate any high level feature differences you can think of.