Boox Note Air2 Plus can't get to EDL mode

[teiosteppa]

Hello everyone, I've lurked around here ever since I purchased a BOOX Note Air2+ last year, and I'm posting now with hope I can get my device unbricked.

After firmware 4.1 released I attempted to re-flash the original full UFS backup I took of my device (on 4.0.2), as I was running into some odd issues. I've flashed this series of LUN images in the past without issues so I can confirm the integrity of the backup.
Unfortunately after restoring this backup from 4.1, my device is seemingly stuck in fastboot mode, and I have no clue how to get it out. The power button on the Boox has a solid magenta light, which occasionally goes blue (which I think is just a battery indicator but I'm not sure). I get nothing in ADB - the device does pop up in fastboot immediately, but no combination of `fastboot reboot recovery` / `fastboot reboot bootloader` seems to give me a different result.

I did purchase an EDL 9008 cable (this one) but despite that I still can't seem to get it into EDL mode. I can't tell if this is because the EDL cable is nonfunctional, or if it's just because my device is bootlooping (when holding the button, the power LED never fully turns off for more than a second, it just alternates between magenta/blue and appears in fastboot). Maybe I need to disconnect the battery to get it fully powered off before trying the EDL cable?

Any advice on next steps would be greatly appreciated. I'm close to just reaching out to their support & paying to send it off but I'm not sure if it's even supported. Thank you in advance!!!

[Renate]

EDL cables need:

• A reset while holding the button
• Functioning xbl, abl, cmnlib, rpm, tz...
• The OEM having put the USB D+ test in abl

EDL test points need:

• A reset while shorting the points