To better answer the question...
My Seaskin undergarment has a zip on the top and bottom. I fully zip up and then raise the lower zipper enough to connect. I then route the hose up into my undergarment with my unit pointing up. Then I zip back down and call it a day, ready to go. I pre-dive pee, while standing away from the gear up area, to make sure everything is correct before I don my rig most of the time. No unusual pressure means I'm good to go.
For my DUI undergarment it has the same double zip setup. Run the bottom zipper up, hose goes in and routed down leg then looped back up. The tree hangs out the fly of my base layer with the bushes still inside. Haven’t run into any restriction problems with this configuration and it’s comfortable.
For my fleece sweatpants I had a button hole sewn in the inseam that I can route the hose through, creating the same loop and setup between the pants and base layer. Trying to bring the hose up and over the waistband led to pulling down on the waistband that wasn’t as comfortable.