SVGnest won't accept SVG files exported from Lightburn

I Agree.
Having said that i have a small machine, the “K40” style, so often i need to split parts, laser the parts, and then glue these together so i wish for nesting program to help me out but as you all said - sometimes we humans do things better and faster. it all depends on the workload. i can’t see any 3D printing service provider who prints daily on many commercial SLS machines without the use of a 3D nesting software. no way around this.