DC and Cummins both repeat the Diesel engine manufactures association statement, which is basically we are sure B5 is fine, but we don't have the data to support higher levels. That position hasn't been updated for several years as far as I can tell, so is likely outdated.
A stock vehicle running B20 is considered by the EPA as an alternative fueled vehicle, so there are lots of fleets running that blend. I assume if there was a big issue we would have heard something.
All that said, HPCR injection is fairly new, so much of the long term data is probably from pre HPCR systems.
DC is filling Jeep Liberty diesel's with B5 at the factory