The 1.5 hrs quoted in your JPMS is a direct migration of CAP371 which is the law. It is to ensure that you are not fatigued through travel at the start of duty.Alleviations are possible to facilitate dual bases.
To ignore this means you are exposing yourself and the company to liability in the event of an incident. More than 1.5 hrs means not rested and therefore to work you are breaking the law.
Yet another worm creeping out of the can thanks to Bassa. Its not just applicible to air commuters but everyone who travels further than 1.5 hrs to get to work but even worse if you are not correctly acclimatised when commuting from another timezone grater than 2hrs wide where you have been for more than 3 local nights
There are many ways the company can get you if they choose to cover their legalities.