V1... Ooops,
The torque limits for cruise, and torque limits for take off always existed in earlier revisions of the POH, it's just the climb limit that has been added. The T5 limit and all the other data in the limitations section of the POH remain unchanged apart from the additional requirement not to exceed the torque for climb limit described in the performance section. Is your comment about the climb exceedances from observation or has that come from another source? There was a huge amount of discussion on the caravan pilots forum when those limits were introduced - the general consensus was that if you approached the T5 limit before you reached the new torque for climb limit the engine needed to visit the shop.
Yes the -114A in the C208 also has permissive transient limits - particularly the torque limit. Whilst I've been told that there are additional maintenance requirements depending on the length of time and peak torque I have not found any reference to it in the POH. As I've never seen the maintenance manual I can't verify whether the above statement is true.
I am assuming that the 'world record -27' holder is flying DHC-6s which you have already advised have airframe power limits nearly 10% lower than those permitted by the engine manufacturer. The -114A as installed in the C208 operates at the engine manufacturers rating - this engine was derived from the 600HP -114 (I think the change was to the compressor section). Additionally, the profile of the operation (altitudes for take off, temperatures and cycles, engine temperature before start) determines the T5 patterns. Even at rated takeoff power none of our engines reach the climb T5 limit during sea level takeoffs (99.5% of our operation is at low level - the only freshwater our floats usually see is out of a hose or the sky). It is for these reasons that I still treat this particular argument with a good deal of skepticism.
One of the other changes in REV 7 of the POH was the addition of recommendations to restrict T5 and oil temperature to a narrower range than the documented limits to ensure the longevity of the engine. When I get a chance I'll dig out the actual wording - it might take a while as a fracture in my right foot has me flying a desk at the moment.
Regards
werbil.
PS What I've seen of the 400 series looks great. Are there any decent photos of her on the water - it would make a great desktop for the PC. Now if only the company could justify putting one on line ...... but then they'd never be able to get rid of me.