I just ran a shot of 5/8" tubing from the pump right up the back of the machine and in through the opening in the top of the enclosure. There isn’t enough room in the energy chain for the larger tubing. I’m not sure about the wash down bar question, I think you really run out of coolant not pressure in that situation because of the size of the tank. I am very pleased that most of the chips (80%ish) are getting washed right down any way with all of this flow. I am adding a separate washdown pump instead with a spray nozzle. It won’t rob the coolant from the operations as it will be used when the other pump is off.
As far as upgrading the the plumbing only you can test that easy enough, don’t worry about routing the hose permanently for the test just hook it up and see what happens, I have my doubts but it all depends on how much flow you’re looking for.