Not sure if it will help much, but I made notes on each hole to ascertain whether it was playing longer or shorter than i thought.
I too was struggling to get below 60, then on one round, I eagled hole 2 and landed a HIO on hole 8 (the par 3 I think). At that point I closed the game client, because I'm a superstitious sod, and I didn't want the VEM, and went on to shoot a 56.
It won't help much, I know, but it's the first time I've qualified .....at the moment ( I've missed out by one stroke on the previous 4 Opens).