If you are only getting 100'pm rate in the second segment you have done the sums wrong.

The climb gradients are none negotiable. And they are independent of obstacles which may require more.

well.... nobody seems to contest that type of performance in the stated conditions... are we all doing something wrong? if so, I'm eager to learn, that's why I posted

100fpm? The aircraft flies 2 miles and climbs 100 feet? How is that possible, in a powerful twin, still meeting regs?

I remember the old line. What happens to a piston twin when it loses an engine on TO?
It rolls and crashes, or crashes on runway heading.

Dicky old boy, your minimum gross gradient in the second segment is 2.4%. So take a look at your V2 speed. Im guessing it's more than 120kts but lets use that as a convenient figure and go with still air so yer speed over the ground is approximately the same. Now in old money that would be 2 nm a minute or 12152 ft per minute. So your minimum rate of climb is 2.4% of 12152 =292fpm.

Hence 100fpm is about 33% of the minimum allowable climb rate!

Ergo you did the sums wrong.

Oh and an even quicker way is just times your groundspeed by the gradient to get RoC. I.e. 2.4 X 120 =288