a highly rigid organization can't really do much about that especially when their core precepts start to fall apart in terms of plausibility and ethics

Yeah, I don't think any religion that has codified detailed belief requirements holds up under scrutiny in terms of plausibility. I think that's why we focus on the "fruits" of "spirituality". I mean, what can you really "know" other than that you sense or desire something more and this-or-that-path helps you connect with that aspect of your humanity to some fulfilling benefit.

if they're really trying to help people gain more "spirituality" they'd kind of have to accept that the development involved might move those people beyond their control or influence.

And there's the catch 22. D&C 121:39 contains, to my mind, one of the most prescient warnings scripture: "We have learned by sad experience that it is the nature and disposition of almost all men, as soon as they get a little authority, as they suppose, they will immediately begin to exercise unrighteous dominion." Of course, the "almost" in "almost all men" means "not including us".