Yes, but it could also be far easier than you’d think as well. Will never know unless attempted.
1.True it’s a safety feature, but it’s also very possible that the seats are easily interchangeable as well. The seat belts/pretensioners are independent of the seats, and long as original belts & buckles are used. For example, I’ve got a fully functional heated/cooled leather driver seat from in Infiniti M45 in my 2008 Dodge work truck using the original dodge seat belt/buckle. I think you could be giving Mazda too much credit here about the car “recognizing” the seat considering the cx-5 memory seats don’t even store mirror settings.
2. very true, but if the seats bolt in and share similar connectors for sensors (very likely Mazda would use a similar sensory system across models), I don’t see a problem
3. Good question...only practical way to figure out is give it a try. Of course that would require finding a cooperating person with a cx-9 that wouldn’t mind wasting an afternoon temporarily swapping seats.
Have lived with the stock seats now for 7 months/23k miles. I think that’s enough time to evaluate how comfortable they are. I will say that they aren’t so horrible that a change is absolutely necessary, but having a more comfortable seat would certainly enhance the driving/ownership experience. And it appears I’m not the only one that feels this way.