I haven't been able to find many Pleasure-Way owners mods at all on the web.
You could mount high quality AGM batteries inside the van.
Lifeline probably has the highest standards when it comes to AGMs.
From their website:
Lifeline Advanced AGM is more efficient in the AGM process and
completes its gas recombination near the plates. In fact, they are
the only RV batteries to pass the rigid MILITARY-SPECIFICATION for
non-gassing even during severe overcharge.
I don't mind using Gels or AGMs inside my Roadtrek. Mazda actually used an AGM battery in the trunk on their Miata's.
I have eight 17ah 12v gel batteries in my RT now. 366ah total capacity in my Roadtrek when you add the two 115ah wet cell batteries in the two exterior compartments.
They work great for me even though the idea is a little bit crazy.