Anyone changed alternator to remote adj regulator for charging lithium batteries?

[Diesel Jimbo]

I have a 7.3L Powerstroke with the dual alternator option. Has anyone tried modifying the secondary 6G alternator to change from the internal regulator to an external adjustable regulator as used often in the marine applications? I found adjustable external regulators even on Amazon which are Ford compatible and adjustable up to 16 or more volts. I would modify the wiring of the secondary alternator so that it would supply power to a separate lithium or AGM battery which both need higher charging voltages than the truck's maintenance free battery. The ground for both power systems would be the same.

Any comments would be welcome!