Found this Saleae-clone 24MHz 8Channel Logic Analyzer on BangGood recently, so it seemed the only thing to do was buy it. I was compelled.
Gave it a quick try on my UV Box controller, and it seems to do what it should - it uses the Saleae software.
For £5 it doesn’t come with probe hooks of course, so now I need to find some reasonably-priced ones…
£6.07 from UK, £5.39 from CN.