I can't imagine ever selling my Kemper but if I did I would sell it as is (profiles, performances and personal tweaks) and include a thumb drive with all of my Kemper profiles and stuff and delete same on my PC. I am a computer packrat by nature. I have every firmware update, every Rig Manager update and every backup I have done since I bought mine used in March 2019. The paid profiles were all purchased and paid for. I would consider the licenses transferred to the new owner and call it a day. Is that legal? I don't know and I don't really care. The disclaimers on the paid profilers sites are about as clear as mud. All they need is one more sentence that starts with "If you ever sell your Kemper...". Problem solved.
If I decided to clear my Kemper before sale I'd simply delete all the profiles and performances and download and install some of the current free profiles available in the downloads section. I would not do a factory reset and force the new owner down that firmware upgrade rabbit hole. The new owner can do that if they so desire. Then they will be here asking for help and being told RTFM.
As I said, this is all moot since I'll sell my Kemper right after I sell my beloved 1984 Gibson Explorer but that's my story and I'm sticking to it.
Truth. Sorry, I didn't mean factory reset as in going back to earlier versions. That would be a nightmare. I just meant a clean system running the latest stable firmware. My bad.