Arcal 76
Let me understand your situation correctly. Your company buys the best-in-class medium helicopter because it has excellent Cat A performance. Of course your company principle must understand that Cat A is essentially a focus on OEI operations but is an excellent guide to safe AEO operations courtesy of the conservative nature of the WAT curves in this context.
To then accept operations above the Cat A WAT or profiles outside the RFM specifications puts you in that grey area of helicopter operations where a safe outcome is entirely down to the pilots skill and judgement.
The basic tenet of Cat A Ops is that they are predictable. That is why PC1 ops are not possible offshore. That environment involves operations within an unpredictable obstacle environment and we have to consider wind generated turbulence and turbine exhaust heat-pollution as 'obstacles'.
To buy a cat A capable machine like the 139 and then use it Cat B is possible, feasible and practical but it is a bit like saying that because you wear your seat belt whilst driving your car you can drive like a crazy man. Ultimately you will ask your car to do something it is unable to do and then you cannot blame the car when you crash it.
If you elect not to work within the Cat A WAT then be sure you have the skill, be sure you have the judgement, then do not blame the aircraft when you stoof-in. The learning curve in this respect is greased with 'luck' and over the years I have used up my fair share. If I can pass on my experiences to good effect and save you from becoming a statistic then here's a pearl of wisdom.
"Read as many accident reports as you are able and be sure that someone else's misfortune is your free lesson in survival."
G.