I'd love to have one. But there's no chance whatsoever that they'll make a Gen 5 regular cab. At least not for the US market.
There's some weird emissions related rule that makes it tricky for them to have a small footprint (physically, as seen from above). As I recall, a regular cab longbed is okay, a crew cab with a microbed is better.
Anyway, I don't see why a regular cab TRX would be any deadlier than a Trackhawk. At least not by much.