You have 22 certified rides. Ive not looked them up but i suspect your portfolio is divers by now.
You ride formula seems to work so why the diabolical next step?
Gatey, think of the bladder decisions like you might think about auxiliary fuel cell decisions hinted at by Jon Kerr. The probelms are the same, even though the fluids flow the opposite direction.
The size of the fuel tank on the bike ridden contributes to your route planning as it can affect the range you can travel before putting your feet on the ground.
The functional size of your bladder contributes to your route planning the same way.
If you have been riding a BMWR1200GSA, its like having a big bladder. You can ride a long way before needing to put your feet on the ground.
Lets say as you age, you can't quite handle the GSA any more. You get a GS, or maybe even a an R1200R. The engine is about the same, but with a smaller tank so you have to stop more often. Like the prostate getting bigger and your bladder getting smaller, you now find yourself stopping nearly twice as much.
Your mates say just stop more often for fuel at a gas station or carry a jerry can and fill up on the side of the road (just like stopping to have a pee behind a tree).
That may be ok on a SS1600K/SS1000M, there is time.
Now suppose after a few years that you get a bike with an even smaller tank. At the same time your bladder may also be getting smaller. In either case a volume limitation is really starting to impact on planning for standard rides if you can't even go 2 hours and a BBG is starting to look nearly impossible. No amount of advice from your mates about where to stop can get around the fact that you need to stop at least a dozen times per day for a fluid exchange.
The "diabolical next step" as you call it, should be very familiar to you personally. No, not the catheter. The auxiliary fuel cell. You make fuel cells for guys that want to be able to ride farther without having to put their feet on the ground. You get a container of some kind, run a tube from it and drill it into the bike's tank. That's exactly what a catheter with a leg bag is.
Now being non-toxic, a dribble of urine along a road won't cause any harm, so most opt to ditch the leg bag. That would be like running the Iron Butt Rally with an aux cell so big you never needed to stop for gas.
I suspect that in the next few decades we'll be discussing how to hook up auxiliary solar panels to our bikes to get farther before stopping to let the sun top up the batteries. Keep an eye out for little puddles next to the eBikes parked on the side of the road.