You got the replacement unit instead of a deck mount PD so that's that.
You still have that working WFCO "lower portion" that you will be removing. You can use that as a home-made deck mount up front by keeping it in a well-ventilated box since it does not have a full enclosure.
It should do its 14.4 that close to the batteries on some #4, but as designed (13.2 trigger) only if the batts are just under 50% approx.
Your gen should run both converters so they add their amps if you can get the WFCO going first at 14.4 with the PD off and then use the CW on the PD to make it do 14.4 too.