Not the answer you want, but as long as the upward loop is below the tank level, there shouldn't be any issue.
A braided line would be badass though. Although I like to clear to be able to do a quick spot check.
White residue could be from leaking coolant into that cylinder. Did you replace o-rings on head? If you don't know the dome size, might want to think about taking some measurements and getting a set cut that you know is good.
Well they've already got some people/builders wanting to make sure their shit doesn't look bad (which I partly understand). Problem is that's not why they are doing the testing. No one wants to have their cylinders ported to exact specifications just to have a set of pipes work perfect.