Man, that's a short BOM on the Fox. Tube for the receiver, and a frame so simple you could cast it.
A Fox with the valve stem partially balanced to let you run a bigger valve stem and lower pressures which reducing the sear friction would be pretty cool. Probably even switch the bolt to aluminum while I'm in there.
...Actually since you lowered the pressure might as well use a cheapy little solenoid instead of a sear system at all, with how cheap a basic board could be.
...Probably easier to throw a dirt simple moving base type reg in the foregrip since you can't rightfully keep the reg in the body what with the solenoid we added.
...Shoot, throw a basic set of breakbeam eyes in and maybe some mass producible plastic shells just to make it look halfway modern, and you'd really be cooking. Every new player could have access to the same ramping firepower as "the pros"! It's gonna be great, guys!
The only problem is that all these changes are so logical, every time a new gun comes out, people will say "it looks/works/shoots like a Desert Fox".