I think this thread has disappeared into paranoid la-la land, and I smell some "manufacturer A is awful, B is so much better" creeping in. In this regard, the issue is physics, not brand labels. Some facts that I think every manufacturer's test pilots would endorse:
1) All approved procedure actually work, as tested by the national regulatory agency (FAA or EASA). If you don't think so, then I ask "Where does your paranoia end? Transmissions? Tire pressure?"
2) Having flown the development and certification of literally two dozen different procedures, I can attest that some vertical climb rate has a measurable effect of payload, to the tune of about 1 passenger, over a slow rise. The vertical inertia is of benefit popping over the TDP, where the most critical factor is the tail cone clearing the deck edge, or the 35 foot dip at the lowest point. That being said, the flyability of the procedure is the main point, so the observations that torque maintenance while climbing up is a big deal are correct. The most successful machines at the fast vertical portion are those where you don't have to look at the torque, just pull against a limiter that tends the power for you. That being said, passenger comfort and acceptance are important. I know of one noble VVIP who stopped at the forward window and asked his pilot "Do you have to do that F%#k-All over the top nonsense again today?"
2) Going straight up, or going slightly backwards are both roughly the same, going slightly backwards has the virtue of keeping the reject area in sight, it has the weakness of needing clear space behind you. There is no magic to it as opposed to going straight up.
3) The key to performance in vertical procedures is always and specifically the power remaining while OEI as compared to the power needed to HOGE at the procedure weight. There is some positive effect from rotor inertia, but it only affects the first few seconds, so its influence is usually only at the very bottom of the procedure.
4) Going vertical costs a lot in lost performance. Helos that are very good at vertical procedures throw away payload that could have been carried, a great 14,000 lb helo that can hover OGE on one engine is actually a good 19,000 lb helo that left 5,000 lbs of payload sitting on the ground.
5) Big OEI power ratios also mean a big gas bill at longer ranges. An engine that is loafing because it has an equally powerful twin sitting next door (both cruising at about 50% of max power) chews up about 20% more fuel for each mile, so that the payload at range for a super-vertical helo is actually less than a less capable vertical machine. In fact, in general single engine helos burn 10% less fuel than marginal twins, and 30% less fuel than powerful twins. Three engine helos burn 30 to 40% more fuel than singles, BTW.
6) The constant demand for superb OEI capability robs safety. The weight in engines, fuel and lost payload spent making you immune to engine failure in the 10 seconds of takeoff rob you of a hundred more important safety features that we leave off to save their weight. The issue is not engine safety, it is overall safety, which is not helped one bit by OEI immunity. Any OEI power above PC2 with calculated exposure is wasted, and could have gotten you improved safety.