HeliTester - yes, that is exactly what my RFM does.
AnFI - If you fly at Vtoss, the manufacturer guarantees you will be able to achieve the PC1 profile, whether or not it is actually maximising the theoretical performance of the aircraft or not - if you don't and you f**k it up, your licence is on the line. Hardly Vtosh - it is stipulated for good reason.
As Nick says, Vx is zero for an aircraft with an adequate power margin but until we start getting helicopters where OEI power is equal to AEO power, there will need to be carefully calculated and repeatable figures available to cater for engine failure at critical stages of flight.
Perhaps you don't fly PC1 profiles or, as ever, you have a better way of doing it.
HNY