Dave McKeegan isn’t who offered to fund a flat earther. He was himself funded by the guy who arranged the whole thing, same as the flat earther was. Dave McKeegan was simply a prominent debunker with skills as a photographer who accepted to take part in this venture.
I dual booted my study pc. Well technically I did. I didn’t use windows for a few months without thinking about it and by then I was too afraid of windows corrupting my linux if I ever booted it. So I effectively just had a Linux machine with half half the disk space. Never had a problem with it though.