∞
@Denny fair point about the differences. I've ended up on dev beta 7; I was going to update to the most recent public data, but the beta options disappeared from my software update settings screen. Fixed that by downloading a configuration profile (the way we used to do it up to 16.4 or thereabouts). Turns out the profile I selected was the dev beta track, and here I am. Less crashy thus far. A few widget issues, but nothing show-stopping. So far, so good... (touch wood)