Ok I can run some numbers on these airports.
They are not in out database (Don't fly there) do you have the obstacle information for each runway?
At the first airport you mention it appears that the runway slop would exceed the allowed limit as it has a 2.39% slope.
PT6
Do you know of some ATR 72-212A (PW127F) that are using this airport? that is the only aircraft I can run the numbers for.