Hello again guys! I'm curious to know how accurate can be HP set?
I'll fly from my house, but it's not a large space, like an wide area. So if I turn to return to home point, I would know how far it can error the distance? Like some cms, or even a meter? Just to make sure.

Home point is as accurate as consumer GPS technology allows.
Mostly it will be within 2.5 metres.
Often it will be closer than that but it could sometimes be a little more.

If you have a P4 pro or Adv and enbale the Precision landing feature and use it where the ground is suitable, you can have RTH landings within a few centimetres.
But none of this makes any difference anyway.
You can choose a better landing spot yourself.
So cancel RTH and resume control and land (or catch) for yourself.

While not a book answer, based on my own experience and experiments results have shown that it returns within a foot or less using/enabling precision landing

You need to refer to the manaul, to use precision landing you have to take off and hover over the landing site i.e. takeoff going straight up.  This is so the downward vision system can capture an image of the landing area to use upon return.

Precision landing is recommended. Please refer below:

Thanks Susan