Idle control - load rpm power accelerator position

[forredtran]

At idle in 1st move forward - no need to touch the accelerator.
At idle in reverse move backwards - no need to touch the accelerator.

My vehicle:
FORWARDS.
At idle in 1st move forward for about 4 seconds - engine slows. It does this just as one would want to accelerate more - accelerator not touched. Sometimes touch the accelerator = no increase in power.
Sometimes touch the accelerator on a hill = engine almost dies or engine slogs up incline.

After 4 seconds the power drops.

On the flat at idle move forward for about 4 seconds touch accelerator vehicle accelerates as it should. It can be difficult to judge the moment to touch the accelerator.

REVERSE.
At idle in reverse move backwards vehicle maintains momentum - go backwards up a hill momentum is maintained. Can feel the power/rpm change coming from the engine which maintains momentum.

It is to do with engine power at given rpm relative to load.

What is it called - the control of the vehicles movement without touching/using the accelerator?

Just found it is called Anti stall and there is a pedal test feature in Forscan.

Can the engine response be adjusted using Forscan?