The manual gives you only this:

"If you prefer fast head speed spoolup (3 ­- 5s) you can use Fast spoolup option.
For the initial setup we recommend normal option."

On my ESC I selected "Heli Governor Off". (Hobbywing 50A V3)
In other words, the ESC is taking care of the spoolup.

So the question is, what is it exactly?
How can we use it?

Governor Off option is correct.

It will work fine. Our governor is implementing own spoolup so you can select spoolup rate by option in Mode parameter.
Mode with Fast spoolup is faster one.

_________________
Spirit System developer

All clear.

I was thinking, maybe this is related to the "Autorotation Bailout Mode" I know from my V-Bar.
However that is not the case as I understand.
Thx for explaining.

I'll test which spoolup I like the most and use that.
Starting with the default.