Maybe the question could be sharpened: "Can you tell about some examples where an IC in your company had a good feature idea, and what ended up happening?"

The problem there is that there's always ONE example. If you ask this in a Google interview, I guarantee they will tell you that "GMail started as a 20% project."

To me, a better signal is a set, repeatable process in place. Does it happen often enough that people know what to do? When they tell you a story, they probably will minimize the gauntlet the innovator had to run.

But then nobody is going to say "yeah mostly we ignore them", they're going to come up with 1-2 examples when they actually implemented it.

Lol yeah, IC starts a company on the side.