they should use a thicker line to represent 1 foot on the pitch, and start it at the last defender, if the attacker is not protruding through the other side of line, then not offside.
It would be very easy to see any body part protruding out the other side, and because of the line's width, in cases where players are very close, then those will be always onside being within a foot of each other, no more 2 inch offsides.
I honestly think that would work well, the Mane offside, by rules legitimate, but for football, soul destroying