mkfs.jffs2 why blocksize less than 8KiB are not allowed ?

[Sigmatador]

When I'm playing with the block2mtd emulation, I need to create JFFS2
image that have a blocksize of 0x1000, it won't work with any other
value .However, the standard mkfs.jffs2 doesn't allow value less than
0x2000 and I have to patch it myself in order to create proper image.

Did I miss something about the way to use the block2mtd module or
mkfs.jffs2 ? Or maybe the limit should be lowered to 0x1000 ?

Regards.