In the big plan I would use the slightly bigger tube and reassess the pressure, it will help you’re veins and ligaments to stretch in more than 1 way.
In my experience is that it’s not an issue that the glans is touching the way, and my glans and part of shaft are the same size. I prefer it for consistency.
When changing your tube be careful with the pressure and liquid buildup, reduce time and/or pressure temporarily.
With high pressure pumping it would keep the smaller one, or like I said reduce/retrain the pressure with the bigger tube.