UBIFS support for SLC and MLC

[John]

I'm exploring flash memory technology for a new product and am
confused about whether UBIFS fully supports SLC and MLC NAND.  When I
read the FAQ at
http://www.linux-mtd.infradead.org/faq/ubifs.html#L_ubifs_mlc, it
states that one of the two aspects of MLC that are not supported is
"program disturb".  However, the document link referenced in the same
FAQ (http://www.linux-mtd.infradead.org/faq/ubifs.html#L_ubifs_mlc)
states that "program disturb" is common to both SLC and MLC - just at
different error rates.

1.  How does UBIFS address the "program disturb" effect in SLC NAND?

2.  Why doesn't the FAQs explanation for how UBIFS handles "read
disturb" apply to "program disturb"?

Thanks,
John