I think we‘re in a very different situation right now. Proton has become so good that it‘s just not necessary for most developers to do anything to get their game running on Linux. When Macs peaked in the hardware survey, the compatibility tools were far less powerful and developers had to actually invest time and resources, if they wanted their game running on Mac.
I also think that the Steam Deck is absolutely being recognized by many developers. Even big publishers proudly announce their games being playable on it. And having games optimized for Deck often improves them on Linux in general.
So I really wouldn’t worry about developers not specifically targeting Linux. Even without that, gaming on Linux is in the best spot it has ever been and is steadily improving.
I‘ve ordered an M8 to Germany last year, the import fees were 147.17€. The whole process was handled by DHL, so I just had to pay that fee online and got the package a day later or so.