Hence my earlier suggestion... BEV with a fuel cell range-extender. Most of the mechanical bits between a BEV and a FCV are the same.
If they're FCV then yeah there could be some batteries, for downhill and braking regen and such it would make sense to put a few kWh in for everybody. But heavy on the batteries with hydrogen as a secondary range extender...depends. I should clarify, I see two common cases for a super duty buyer IMO:
1. Local contractors--builders, lawn services, etc. Yeah, I agree it's a good suggestion, a range extender would work really well here. They can do their daily routes mostly on EV and then have the backup if they need to go out of town for materials or something.
2. Transporters (aka, fuel superusers from the earlier thread)--people moving cars/materials/supplies/purchases/campers over some distance for hire or for personal use. I and most other amateur racers fall into this category. If I'm towing, it's almost always hundreds of miles. Even if we could fit a 100kWh pack along with a FC into one of these things, on a median 20k GCWR journey that
might get me 10% of the way. That other 90% would be all hydrogen and I'd want as big a tank as possible. Consumption is huge; to illustrate, I currently get 10-10.5 mpg with my 20' enclosed race trailer. So if I have a race at VIR, that's 60 gallons of gas each way. With my 26 gallon tank I still have to fuel up four times on the journey, and that's starting with a full tank. It's actually one of the reasons I didn't get the PHEV version of my car; it doesn't really change towing MPG but the tank is 6.5 gallons smaller.