I've just installed a secondary fusebox in the cab. This is for radio/chargers/table light and is powered from the LB.
My LB is on the l/h/s of the engine compartment and the wire runs through the front of the engine bulkhead alongside an existing brake light cable under the van, into the pedal pan, and up through another existing hole in the front inner valance into the cab.
I was going to use plastic split conduit but I think it will be ok as it is.
HTH