If you disable PATS, the car gets stolen, and the insurance company finds out you disabled your anti-theft.... No more insurance..
Your premium you pay is based on the features your car has. ABS, Air bags, PATS, etc. Since you no longer have some of those features the insurance company can deny your claim and/or it will make it very hard for you to get your money.
It's the same as someone stealing your car when it's unlocked and the keys are in it. You need to make the effort to secure your possessions, not rely on insurance so you don't have to think...
Riley