Another success story: USA O3DS, 9.9 to 9.2. Got a black screen after SysUpdater's reboot, but I removed my SD card and booted it again, et voila, 9.2! Thanks so much to everyone involved!
Hopefully I'm not knocking on wood... I'm feeling so ecstatic that I can't test anything yet.
I got a US New 3ds XL too. May I ask, is it necessary to remove the 000400102002CA00 title (i suppose this means the relevant cia file)? Insofar I am not aware of the said title cia file in my updates files.
Any reply would be appreciated.