So the reason people are allowed to update their backups in OFW is because the Switch can download game updates for games displayed on the home menu. This is extremely easy to test. Just try downloading an update for a game that you have physical but without the cartridge inserted. The Switch retains its icon there, for some strange reason. The reason they cannot detect this is because its functionally the same as borrowing a friend's cartridge and playing it on your Switch then keeping it up to date in case your friend lends you the game. They could believe its suspicious you're constantly updating a game that you have little to no play time with online but its a hard call to make.How is it that you know Nintendo can't tell the difference between updating a backup? Especially for people updating backups without original certs headers..
Isn't what you're saying purely speculation based on.. what.. your own knowledge? Which is? Do you have some links, articles, proof?
Also, a headerless backup=a retail cartridge. The only difference is one has the ability to go online while the other does not. All game dumps should not differ otherwise because then that would mean people would be playing a different game. The differences lie somewhere in the certificate hence why it is recommended to never share the certificate with someone else because Nintendo can track this since it is unique to each cartridge.