Is spoofing still not an option? In my case, I have two Switches - one is on SX Pro 6.1 and the other is new, but will have to be updated to 6.2 in order to remain official for downloading game updates. Since I can't find a tool to convert installed game updates on an SD card to a .NSP file, the only other option I can think of to get game updates on the first Switch is to use the feature to
update from another Switch, but for that to work they both need to be on the same firmware. If the SX PRO emuNAND can pretend to be on 6.2 when talking to another Switch, this would work.
If not, well, 6.2 doesn't currently work for SX OS. The keys have been dumped, but even when it does work updating will be rather annoying. If I use choidujour to update the emuNAND, the moment it boots into official firmware the eFuses will burn and the Switch will act like it was just downgraded and then freak out because the eFuses don't match. If I use autorcm I'd have to deal with the battery issues, and if I don't then any random game launch error can force it to reboot into official firmware which will then of course burn the eFuses. That means my only option would be to backup all my saves, restore the NAND to the backup I took right before setting up emuNAND, then create the emuNAND again, then restore those saves and of course will have to reinstall all the NSP games - and I would have to do that every time a system update occurs.
So then the only viable options for me would be spoofing the firmware. If that was a thing I could just keep the emuNAND on 6.1 indefinitely and just not worry about it.