Well, I don't have a DakotaCub frame, just a highly modified Piper one, but I imagine they are about the same.
Here's what we did to accomodate the left hand door:
Right hand/Starboard Tank Rear.
Ran the right hand line down to the horizontal tube between the upper longerons. crossed the fuselage behind the dog-legged brace in front of the lower baggage. Under the baggage floor, welded a tab with two holes just above the fabric and installed a T in the line, with a quick drain in the inboard hole matching up with the leg of the T to provide a low point drain.
Continued the line below the door to below the fuel valve then up to T with front line.
Right tank front
Down the door post forward to firewall always sloping down to connect to a T with the rear line at the fuel valve.
Left rear, down and back to baggage then beside the right line down under floorboard to outboard hole in welded tab with T and quick drain.
Left front down door post, behind throttle, connect up to T with rear and then into fuel valve.
Vent line remained in stock overhead position
All of this was field approved with a PA-18 style fuel valve because my mechanics wanted to get away from the 56 year old dual valves. Oh, and the tank STC required the right front line in this case.
I have a rough drawing somewhere if you want to pm me your e-mail address I'll send it to you.
KL