No, no I (and most other people) don’t. If you do, that’s an unusual quirk of your own.
‘Gno’ is meaningless. (Well, I use it occasionally, but only to tease a friend who plays gnomes in D&D a lot. And there it’s a ‘gnomification’ of ‘no’, not ‘know’.)
If you’re going to reform spelling to remove etymological artifacts, why the hell would you replace them with etymological artifacts from different words from different languages, with different prior pronunciations (which just happen to have normalized toward the same pronunciation). This is a bizarre form of hypercorrection.
Reformed spelling of ‘know’ would be ‘no’. Knowledge, likewise, would be ‘nalij’. Gnome would be ‘nom’, and gnostic would be ‘nastik’. Spellings consistent with their most common modern English pronunciations, but completely removed from etymology…