The general consensus indicates running wvo thru your oem fuel system is a bad idea. The oil can polymerize and cause blockages that you cant really get to and clean out... so you end up chasing and changing out fuel system.
Heated pickup alone probably isnt enough to maintain temperature to injectors. For safety sake you want a good 160*f. Some guys say higher.
There are lots of write ups on how guys did their coolant heat exchangers and switching. Its important not to mix your diesel and wvo. Seperate filtration is also a wise option to consider.
Its well documented how to make this work safely for a very long time.
Its also well documented how it doesnt work... and can kill an engine if the wrong shortcuts are taken.
Important things to implement in your onboard system:
Seperate d2/wvo tanks
Seperate pump and filter for each tank.
Seperate fuel lines to the engine where you will tap in AFTER the fuel bowl. Or into the aux fuel ports on the heads.
Implement one way check valves on your oem fuel lines before the wvo tap, or at the heads ifyou run your wvo to the aux ports.
Timed fuel switching on the return fuel... so your d2 has time to return to the d2 tank whole the wvo pushes it out, and visa versa with purging wvo while switching back to d2.
HEAT : you must have a steady, stable heat source to get the oil to the right viscosity to safely run in your motor. The best way to achieve this is by using your engine coolant as a heat source. It warms up quickly after startup and you can switch on the fly running down the road once it gets to temp. Just remember to flip the switch back to d2 30 seconds or so before pulling in to work/home and drive on wvo all the time.