So I'll post this in the form of a question:
Other than the consumption of say 1.75W of battery power for each Jaguar, and the space it consumes...is there any reason that someone couldn't put a a single pole relay normally open contact in series with the H-bridge and then put a diode in series with that relay's coil so that if the power is backwards the coil simply will not energize and connect the H-bridge at all? Would this not completely elimate the risks to the body diodes? Couldn't you perhaps reduce the energy required to power that coil using the control electronics if you wanted to do it a more complicated way (considering you'll only close that relay contact when the polarity is correct and your controller here can easily pump out PWM?)
If so what rating would you all think is fair for those contacts?
How about 70A like these:
Mouser, 70A, 14VDC relays