I think if the board has a Thunderbolt header it should work - should, but doesn't have to, because according to some reports this card doesn't work even in boards that are on the compatibility list. The lists are of course not updated, Chinese / Taiwanese manufacturers never do that; so everything on the websites remains as it was originally done - and thus boards that come later are basically not listed, whether compatible or not. No one can say if it will work in the end, unless someone owns this board and this card. If I were you, I would just buy this part and try to install it. If it doesn't work, you can always sell it at a small loss.

About the right slot: The point is that the card can use 4 lanes, so it depends not only on the settings in the UEFI, but also which board and CPU it is and what other devices are connected to the PCI-E bus.