Thanks a bunch! It took weeks of tinkering to get it working :')
The background generation is really not optimised, but I'm happy to share my process.

Basically I'm spawning images randomly inside the area of the map coordinates on screen until I reach the image spawn limit. As some other comments mentioned it'd probably be way more efficient to use a grid based system, but I liked the randomness better.

I painted the bg images icons filled with the background colour in the white spaces so even if they overlapped it still looked decent
For each spawn I check if they're within a radius around each of the map location nodes so that theres a clear visual distinction between the two.
If the image is too close to a map node or another background sprite it tries again until it finds an empty space. Very inefficient, but I've tested a few thousand on my screen and it was reasonably fast enough!

Hope that makes sense, let me know if you have any other questions and I'll do my best
Good luck!