When I had troubles with devices not reporting properly and not flashing, what helped to some extent was to plug a working device of given kind into port1, letting the updater detect it, then replacing it with the broken one and force-flashing it. It may no longer be possible with the new VexOS update utility though.
When this didn’t work, I had a more involved setup with a spliced VEX cable so I could observe the I2C communication and force the I2C_EN signal low to trigger re-enumeration.
The last step is opening the device in question and flashing the firmware directly using the MSP-Launchpad kit, but that’s more for testing, since the device enclosures are ultrasonic-welded and you have to destroy the enclosure to actually open them.
But contrary to the TriDragon’s conspiracy theory, I have had the best experience with VEX support - they always replaced any non-functional devices free upon presenting proof of purchase, so IMHO it’s VEX who is bleeding for broken parts…