@penguin42 all do yeah, the trick is to run "fastboot set_active a" on every boot, this resets the boot counter.
worth noting that i currently just have the op6/6t hooked up (pic related, details in alt text), and I'm only really confident that i could get the op7, fairphone, and Pixel devices up, the others I'm not quite so sure.
@cas Oh, that's nice. Yeh I found out that qcom problem on my Find7 (main phone) the hard way when playing with kernels. What's the 4.4v for? Seems an odd value.