Great build thread and your heater install reminded me there is another less expensive option besides Espar. That lead me to Google and I immediately came across the link below.
Prior to reading that, I was a little concerned about your exhaust pipe exiting directly under the van and wondered if that might cause any problems. I always thought diesel was not prone to producing carbon monoxide, but aparently that's not so. Carbon monoxide is bad stuff, so be extra carefull. Anyway, I'm loving the build and considering adding a diesel fired heater to my rig. I have another friend who has one and finds that despite relocating it a couple times, the thermostat has trouble keeping a steady temp inside. How well does yours regulate the temp?
My other comment is about the venting of your battery boxes. Since Hydrogen is lighter than air, the vent should be at the top of the box, not the bottom. Anyway, loving the build, I'm looking forward to more photos.