The e2fsck error "Inode 4457806 extent tree (at level 1) could be narrower. Optimize<y>?" can be very noisy (many thousands of lines), and doesn't really improve filesystem performance in any significant way (typically saving a few extent index blocks for files that were written with holes that were later filled in).

It would be better to change the e2fsck default to not optimize the extents, to avoid confusing users with a lot of messages and giving them worries that their filesystem is corrupted.

I've discussed this with Ted already, and he agrees that this is an acceptable change.