Regulator set points are lower because modern under-hood temperatures are higher, and not because of some new profound wizardry in battery design. One way to thwart this is to ensure a good solid voltage supply to the camper then fit a DROK 600-watt DC to DC booster alongside the battery and set it to 14.6 volts.
If a person was a marathon driver coast to coast the voltage would have to be tweaked downward.
As the regulator approaches the magic "Dropout Voltage" of around 1.3 volts differential between incoming and outgoing signal the booster drops out of circuit and the alternator regulator takes over at a lower voltage. The DROK has an integral 20-amp ATO fuse that is easily replaceable.