I agree on the durability aspect of an in-tank versus external tank, to my mind this would be a driver to go with an in-tank however I would rather drill a few small holes and insert rivnuts in the tank to mount the pump rather than welding. As you can see I really don't like welding used tanks...
Firstly, I am not knocking the work and product, both are great but I am curious why this time consuming, seemingly complicated (where even a pro like you gets it fractionally wrong) and possibly dangerous (welding a fuel tank) option was chosen by Mosley over a simple no weld bung option to...