Hi Darrell, no worries , we are just having good old constructive conversation.
I listed two of the reasons that I can think of in my other post, I guess the electrical engineering department at Alliance would be able to share why they chose this route.
@Oregon_Camper comments as well about the demands.
I totally get that in theory that it is not required to make things work and the truck charge line would input to the battery regardless without a DC/DC.
I really think that the main reason is related to battery longevity(health) by providing a sensed and control output to the coach independent of the tow vehicle , and to prevent any 12 volt drain from impacting the tow vehicle given the extra draw of the12 volt frig.
The unit acts as an isolator and will not pass current unless the trigger wire is activated.
Only a guess, but imagine a seniero , where the unit is parked, still hooked up, not plugged into shore power, but having a need to power the frig.
In theory, you could drain the truck battery and not be able to start(without this isolator functionality).
Just offering my .02.
Maybe the A Team could provide more clarity on their strategy.
Best regards,
Bryan