I thought I was the only one. Something with Three.js

THREE.WebGLProgram: Program Info Log: (155,1-6): warning X4000: use of potentially uninitialized variable (dyn_index_vec4_float4_int)

causes the hover highlight pass to fail, so the mask renders as a giant green plane instead of an outline.. I think.

Edit: After importing an unscaled SVG file as an asset for the layout, I showed that the green circle is seemingly an oversized outline highlight but its the 4 corners of it, all at 0, 0. Since my SVG is unscaled its stretching this out to see more what is possibly going on.