Re: It's not You, It's Me
Where the conceptual discussion tends to go astray is with regard to outcome, rather than topic. Some people talk about topics like internal strength skills as if they were a discrete set of physical skills that are meant to enable the physical manifestation of a martial art like aikido. Others talk about the philosophy of aikido and assume the physical practice already includes everything needed to get discrete body skills.
Even within the topic of internal strength, I'd agree a lot of the discussion is around the very baseline table stakes required to have a credible conversation around how internal strength works in aikido. I've yet to see any advanced level topics - partially because no one wants to tip their hand regarding all they know and partially because there's folks out there still furiously trying to gather information regarding the "how's it work".
I still stand by my thought that the aikido techniques, for the most part, are meant to work ki/jin extensions. The spirals and windings that are mentioned tend to run along the inside paths of how the body's knit together and leveraging the strength of the legs, hips and spine moving together to transmit power out the frame via the connective tissues and muscles being conditioned to work together appropriately. There's probably already some divergence in approaches being discussed here regarding how people train to do even that much.
When you look at internal strength in martial arts contexts, it's ultimately about how much power you can generate and release (in a particular kind of way). Not to be too much of a proclaimer (well I would walk 500 miles, and IIII . . no? Fine) but I tend to view these things pretty narrowly through how they're defined well outside of aikido. Since aikido is a fairly modern creation, it's still bound by the well established "rules" of internal strength as it's already understood in the bigger, wider world.