Got quite annoyed by this. Solved fairly quickly (after a pause to unravel the top left hand corner). Had quote and brief. Found follower. Found name in grid. Chambers gave me one item associated with follower’s invention.
Then got stuck, lost patience, checked another site. Not impressed with how little follower has to do with solution, given that the only shortened entry to make perfect inner sense is also the only one which uses an item attributed to the follower. I expect misdirection, but not to that extent.
And Chambers may confirm the other items required for changing cells, but only if you’ve already guessed what they are. As they don’t relate to the follower’s system, I’d suggest there is ambiguity there.
I do admire the final bit of lateral thinking required (and don’t worry, I won’t be posting a solution!), but after a quote has been wrenched out of context to serve a setter’s sadistic whim (standard Listener practice!) and I’m expected to follow it in a rather literal fashion, it’s galling to find that I was looking for a thematic unity that wasn’t there.