Erase block size on CF cards

Couple of questions about erase block size and compact flash cards:

- Does the erase block size matter when using JFFS2 on a compact flash card, via the "blkmtd" or "block2mtd" drivers?

- If it does matter, how can you reliably determine the underlying erase block size on a compact flash card?

So far, I've been assuming an erase block size of 64KiB, but I'd be interested in learning if there's a more optimal configuration.

-Ryan