If you don't want to go the EmuNand route (or if you can not go that route) then you stil have one option to keep your switch safe from getting banned, even though it requires more time and is not as convenient:
1) Go 100% offline in OFW and proceed to enter RCM and Dump the FULL NAND
2) Install CFW, do a full System Format (better be safe than sorry)
3) Wipe the PRODDATA partition with the Incognito tool (again, better be safe than sorry)
4) Use your CFW for whatever you want but stay offline the whole time
You want to play something online?
5) Boot into RCM and proceed to Dump the FULL NAND of your CFW-Hacked Switch
6) Flash your Full Original NAND Backup on your Switch
7) Play your legally bought games Online
Now if you want to boot to CFW all you have to do is to switch between the NAND dumps.
Before switching you should ALWAYS do a new, full dump of your current NAND, so that Logs stay chronological.
(And yes, technically its eMMC, but the term 'NAND' is well known I gues).