Not much depth to my experience, sorry. But I have some minimal exposure.
Two different applications. Specifically PRS guitar amp emulation from Waves, and an IR reverb.
(Speaker cabs In the former, spaces in the latter)
In both cases they appear to have a proprietary data folder in which you can store IR's that you can load from a menu option within the plug-in. And in both cases you can add more IR's from third party sources. They appear to recognize a specific file type.
Then there's the steps to record your own impulses, but I never got that deep into it. I suspected it was one of those ultra geek side-tracking time sucks....
Not that there's anything wrong with that, if that's your thing. I just have to be aware so as to avoid the result of getting NOTHING done on my intended goals.
*But... Having seen a clip where Sylvia Massey records within an empty abandoned nuclear cooling tower and captures an impulse, I can see where this could be quite interesting.
I have seen sources of responses from all sorts of spaces. From famous halls and theaters to all sort of odd locations.
Something cool happens in vertical shafts though.....