Anecdotal but the company I work for does. But, not for the reasons the wider community cares.

Strong FOSS projects tend to have multiple options for commercial support. So, if a hostile company acquires your commercial support provider, looking at you Broadcom, you have some options to move to someone friendlier for support.

So, for my employer it is about having options.

They do if they are building it into their product/commercial offering. Less so if its a direct and internal usage.

Yes. A shitload of legal nuance depending on what you choose here. (Software supply chain issues are increasingly important nowadays, and executives usually care about this stuff more, because it can carry huge risks.)

Those with purchasing 'influence' might. Accounts payable? No.