From someone who has actually been using SX OS, and not someone who hates SX OS for being a paid solution: I've been using SX OS from June until now. I've played backups in SX OS (XCI only, no NSP!), while having removed my internet settings and being in airplane mode simultaneously. Whenever I needed to update backups, or wanted to play online with one of my legitimate games, I booted back into official firmware without restoring a clean NAND backup. I never go online with my backups! I make sure that no internet connection is possible while I'm in SX OS. This means I remove my internet setting in OFW before booting into SX OS. We're closing in on december now, and I have not yet been banned. Last time I went into the e-shop to check if I was banned, was yesterday. It all still works.
My anecdotal lesson from this is as followed:
#1 Only use XCI files. Don't use/install NSP's, unless you're willing to restore a clean NAND every time you want to go online. This also means having to separately backup your saves, and restore them when you install all of the NSP's again. NSP's leave fake tickets on your device, which stay there even after having removed the game. This was proven to cause bans, and Team-Xecutor (TX) discourages the use of it, despite providing the option (at your own peril).
#2 Never go online in SX OS. Never. Remove your internet settings and disable wifi prior to booting into SX OS.
#3 Don't immediately update to a new firmware, unless TX gives the ok that you can do so on the same or newer revision of SX OS.
#4 There's always a chance that in the future, Nintendo adds new telemetry that allows them to detect all the wrong things I did. I am taking into account that some day, I might be banned. But for now, I seem to be safe.
