I been playing/running WMO & WVO since back in '03 & as my signature says
"tremendous learning curve!"
I've installed every kind of heater I could. Heat is the answer!
My set-up now consists of coming out of my heater hose outlet from the engine directly to a 24 plate heat exchanger, from that to my last fuel filter (FS 1212 filter) thru heater hose coiled round the fuel filter. Incidentally I use about a mile of heater hose on my complete set-up.
I run diesel in my front tank, WMO or WVO in my rear tank & my bed tank. I built tank heaters & installed them in each tank, using 1/2" aluminum tubing from Summitt, coiled & running down into, thru, & back out of each tank. Thru the coiled tubing I then circulate my radiator coolant to & thru each fuel tank. Heater hose also laid & insulated next to each fuel line for more heat. My total coolant capacity for my complete set-up is approx 9+ gal.
I also have a fuel filter/screen & a Holly Red mted on my frame with heater hose wrapped round both inside a foil blanket for added heat.
In summary my tanks are heated & insulated. Everything (fuel etc) runs parallel along heater hose or has heater hose coiled round it. Fuel is pulled from tanks & is pushed to/thru the plate heat exchanger then on to the last heater hose wrapped fuel filter (FS1212), then on to the IP.
Heat is the answer!!