Re: A more easily understandabe file tree? Yes, please!
"The need here is for them to be findable, *without* a reboot, using only generic Unix tools such as `which` or `man -k` or `apropos`, or in the desktop's app launcher -- whatever desktop, whatever launcher. It _must_ be cross-desktop or it's NFG."
Then you're chasing unicorns because there will be setups out there that will be intentionally incompatible with another's standard. Any setup you find will not work somewhere. It's like trying to find the one question that will get you the same answer from everyone.