there is what is called Telemetry data on the console itself, that keeps track of pretty much everything that you do on your switch. if you factory reset that report remains, there are ways to wipe but calls for almost an instant ban as you break the natural sequence if it and it flags nintendo when they check it.
That's why the only way to really be safe is to have a clean NAND and restore before doing online activity. An NAND restore everything from the point of the backup, including the telemetry report.
Well I used the Homebrew launcher via the web applet while I was on 3.0.0 - that was way before any of the good RCM exploits happen.
These old homebrew methods weren't very stable and modified the error code to something like *****-1337 or so.
I'm pretty sure these are all over my telemetry data as well.