Hmm...
It might be a useful change for other reasons.
But I agree, better testing is called for to justify changing files in the Amazon image of the filesystem.
Since we can not (yet) de-brick a Kpw, changing files in the Amazon image that might cause an firmware update to fail in way that leaves the Kindle 'bricked' is not a good idea.
Note: There is a patch to U-Boot available from the Freescale Community that will force the SoC to switch to 'Fastboot' mode on the next restart for the MX508 SoC.
A tad bit too invasive of a change to test for my paygrade.