ProMariner suggests not using my charger for LiFePO4

[lateral]

I can understand that, as in RC's " cheepo FET's inability to handle high current" but if the drop in BMS's FET's are rated 150A continuous and your vessel has a margin of safety inside that, are you not gtg?
Can't see why you cannot adjust Pronautic settings to suit and just monitor it.

Without starting a new thread, with the same theme in mind, and if the drop in BMS has hi/lo Voltage relay control, could you not control either the field wire or power wire to your regulator? Leaving you ACR in place to keep start bat charged. Saving the DC/DC rigamarole? If the relay failed I can still turn the key off at helm which depowers regulator.
Can someone point to a thread with least change to FLA house + start battery conversion to LiFePo4? Currently FLA + ACR to start battery. MC714 ext regulator, forced cool air alternator. Pronautic 1250P shore charger.