Sounds reasonable, but it still is a red line figure under limitations. The only marking on the Jets and T-props for red line would be the maximum never exceed. The others would mark the start of a caution range possibly, although the ones I've flown have just had a red line at maximum never exceed and memory items for max continuous, take-off etc... There were also transient power fluctuation numbers that allowed excess rotational forces but never beyond max ITT. It is interesting to note that maximum ITT limits on the jets/jetprops work out about the same at around 1600-1700F.
On another problem, on some Seneca II I've seen skin just aft of the cowl flaps and exhaust that seems to be rippled and warped. The way the exhaust is ducted through the cowl flaps seems to point to this area and looks on the surface like heat damage. Ours never seemed to do this but we were conservative with EGTs etc... Not sure what caused it on these other machines though.