Romanov-
As you, I made a similar spray box ... with the addition of two box fans and filters to suck the spray gun over-spray down.
All worked well for a few priming sessions until the dried primer/paint buildup inside the box began flying up and getting onto the parts being sprayed ... not a big deal for the structural parts, but not what I wanted to see for the painted interior parts. I had to really clean the inside of the box quite well to prevent the dried paint from kicking up ... this was somewhat difficult as I had to work through the fan cutouts.
If I had it to do over again, I would place the cloth wire on a hinged frame to allow for much easier cleaning (which you will need to do at some point) .... just flip up the top, clean the inside of the box using a wire brush, vacuum, then blow remaining dust out with air and close the lid ... the spray box is ready for the next use.
Enjoying watching your build progress.