I hear ya. RowID is definitely more secure. Like I said before, it might be the vulnerability of using a lookup value for row owner, or it may be that a lookup column is not seen as an email column, so the option to make row owner isn’t visible. It’s also possible that Glide just never considered a scenario like yours.
If at all possible, I would attempt to use the array column method if you have multiple users that you need to make the row owner. If you only need one column to indicate row owner, then it could be easier. In either case, you may need to use formulas (such as vlookup) in the google sheet to fill an email column that glide should then allow you to make the row owner against that column.