Really cool, Damage. I’ll really enjoy watching your project evolve. Why not use strips instead of soldering your own boards?
Micro’s right, those are the panels I’m using (with a custom connector). While you can connect multiples, the bezels need to overlap and I’m not sure you can get the adjacent panel LEDs 1cm away as they need to be. Plus, doing a larger grid with them means calculating for the various zig zags, which sounds like a real headache to me.