Pretty sure that my (one of my many) problem(s) over the last few writing weeks is that I've slipped back into a pattern of thinking too linearly. Seems to manifest itself most when working in fiction, so I probably should have spotted it before and recognized it as the problem, or at least part of it. Most likely some residual trepidation about fiction that I was long ago able to (more or less) abandon with non-fiction; like anything, it takes time and practice and the occasional renewing of vows.
Solution: return to "slips of paper" or the zettel/Obsidian way of parsing out individual notes from the notebook cacophony, tag them, and stuff in a project file (or the general digital brain catch-all if devoid of a certain project). Embrace the chaos, resist the urge to organize too soon; order and a whole comes later.
Tagging as Note to Self so I can reference if not the entirety of this piece then at least its title.