Does modern UBI/UBIFS still suffer from the 'unstable bits issue'?

[Tim Harvey]

Greetings,

I have a user with an IMX6 and raw NAND using UBI/UBIFS who has been
able to reproduce a NAND corruption:

[   10.611972] UBIFS (ubi0:2): background thread "ubifs_bgt0_2" started, PID 631
[   10.634365] ubi0 warning: ubi_io_read: error -74 (ECC error) while
reading 253952 bytes from PEB 2807:8192, read only 253952 bytes, retry
[   10.657492] ubi0 warning: ubi_io_read: error -74 (ECC error) while
reading 253952 bytes from PEB 2807:8192, read only 253952 bytes, retry
[   10.681137] ubi0 warning: ubi_io_read: error -74 (ECC error) while
reading 253952 bytes from PEB 2807:8192, read only 253952 bytes, retry
[   10.704267] ubi0 error: ubi_io_read: error -74 (ECC error) while
reading 253952 bytes from PEB 2807:8192, read 253952 bytes

The kernel they are using is a bit out of date but does have
'gpmi-nand: Handle ECC Errors in erased pages' [1] patch

I'm wondering if the 'unstable bits issue' [2] is still an issue or if
the UBI/UBFS Documentation is out of date and this has been resolved.
If it has been resolved, can anyone point me to the patches.

Regards,

Tim

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bd2e778c9ee361c23ccb2b10591712e129d97893
[2] http://www.linux-mtd.infradead.org/doc/ubifs.html#L_unstable_bits