[Levansic]

Going back to the OP's question, I would suggest testing your setup with a nipple, and with the tubing. See if there is enough difference, or even good difference that would be worth risking the creation of a new rule.

One of our mentors had the same thought, and attached one of our higher Cv solenoids to an accumulator with a short brass nipple. Imagine our surprise, when the increased "performance" turned out to be detrimental to the actual performance of our catapult. Everything was promptly changed back.

Test your theory, and find out if you are just tilting at windmills with trying something that will attract attention from inspectors. You will at least satisfy your curiosity, and you may just find, as we did, that it isn't worth it.