Re: Forget the risk of fire spreading through the holes in the wall
>The walls are plasterboard which wouldn’t hold up anything.
But plasterboard over studwork can be structural, and probably is in many new timber framed constructions. Whilst the main weight is carried by the timber frame, the plasterboard stiffens the frame.
A relations house, dating from circa 1860 has a structural timber panel and frame internal wall holding the first floor landing up.