This happens to me with pen and paper all the time. For example I sometimes automatically write "your" using the hiragana or katakana character "yo" with an Eng

This happens to me with pen and paper all the time. For example I sometimes automatically write "your" using the hiragana or katakana character "yo" with an English lowercase r after it. IMO the mind thinks this combination is more appropriate given the sound of the word being written. Similar things happen with writing shorthand, like "yr" for "your" even though I'm trying to write out the full word in regular English and the letterforms should not be regular English when using shorthand anyway, but that's how they come out. Not to discount the possibility that keyboard typing is still somehow different in this way though.