[zozbot234]

> even if the bootloader is loaded from eMMC, in what way is the user impeded?

The "bootloader" isn't just a bootloader, it's effectively a critical firmware component. If the "bootloader" is missing or garbled, the board is bricked and can only be recovered by removing the eMMC, which would be very difficult for most users. Such a thing should not be stored on a data partition and managed like any other distribution package. If they aren't going to ship a separate SPI chip, the eMMC should at least be repartitioned to include a separate "firmware" partition and the bootloader should be shipped there. Distributions should then boot via a chainload mechanism, just like on x86 hardware. (This mechanism can be UEFI based but need not be.)

[Avamander]

> only be recovered by removing the eMMC, which would be very difficult for most users.

No, it would require an SD-card to recover.

[megous]

Not even that, USB cable is enough.

[Brian_K_White]

Are you quite sure about that?

A lot hinges on a fact like that. It's the difference between not-convenient and not-possible.

Will the device actually know how to boot from sdcard if the part they are talking about is broken?