Funbox 3.0 Range: Optical Fiber Setup, 2 Bands 5GHz & 2.4GHz, Large House Coverage, No Antennas

Hello
Yesterday I learned that I will be mounting optical fibers at my place.
I have a fairly large house and I would like to ask people who have or know about funbox 3.0
From what I've read is the ability to operate on 2 bands 5GHz and 2.4GHz is a plus.
It's mainly about the range because unfortunately there are no antennas and I don't know if that translates into it.

You will not predict the coverage in the building, you will check it when you get the router.

I have 3 funbox and I agree it has 2 bands which is a plus, but compared to the previous version it has worse wifi coverage at all in my home. I have a router on the first floor, diagonally on the terrace is very poor range and previously there was no problem, in the basement I catch about 1 line on a smart phone. If you already have cables or the possibility of placing them, consider buying an Access Point and cover the whole house. The question is how many floors do you have, and whether the range of your neighbors enters your surroundings