Seems ludicrous the current interpretation.
99% of your body can be in an onside position yet you can be ruled offside.
This can be fixed relatively easily:
1. It's called football. So you only measure the position of the feet. You then remove the 3d element associated with height of torsos, armpits etc.
2. A. You use the silly lines, but you acknowledge the inaccuracy of around 12cm and have a zone of tolerance. Provided the attacker doesn't have a foot fully beyond this zone, then he is onside.
2. B. Alternatively, you reverse the current logic and have offside only when there are no body feet behind the line.
3. C. Alternatively still, you just have the ref review the incident at pitchside once called to his attention and he makes a judgement by virtue of seeing the replay. Max 60 seconds to overturn.
I'd say all these are more palatable then the current fiasco.
In A, teams would accept if you have a buffer zone and you are beyond that you've had more than enough benefit.
In B, you're allowing any body part being inside accounting for being inside so think this positive slant would be more accepted.
In C, much more akin to clear and obvious with the same ref checking he hasn't made a howler.
For the ref getting in the way, the hitting the ball hitting the ref or obstructing a player / interfering with play are treated the same, as they can clearly leave the same outcome.