The answer to Keygrip's question was actually covered by the introduction of the Koch chart which demonstrates that in fact, density altitude (& not temperature alone) is the limiting factor. Piper & the local FSDO verbally agree in principal that it is safe to extrapolate beyond the published performance data, however, as BillieBob points out, would an insurer accept this in view of the fact that effectively, the aircraft is being operated in an environment not encompassed by the POH? The Warrior suffers the same problem & at schools in other parts of the world where the daily temps. regularly exceed 40C, flying activity stops at lunchtime (Qatar, W.Australia for example).
BillieBob's assertion that
When there is an accident, as there surely will be
can't be attributed to temperature alone though for the reason I've described. In the
event of an incident for an unrelated reason however, I'm sure the NTSB would be interested in determining why the aircraft was operating outside of it's
published envelope.