So after getting past the etcher failing around 50% issue (switched to a spare notebook), I still couldn’t get past 4 green blinks - until I stopped trying to use a project I created a very long time ago (over 12 months).
I created a new project, it has
arm7hf as its arch, burnt the image to sdcard, and it boots, but has ext4 corruption - so failure number 4!
grabbed a different sdcard, used etcher to write the image again, and this time, 2.7.5 dev image boots, but then stops with “Failed to start File system”, and then the other services don’t get started.
I’m going to try 2.3.0-prod next, but gosh i’m having a very long string of bad luck.
(and yup, 2.3.0-prod (and -dev) worked)