Possible investigation: Map alpha transparency to RGB value for modifications quality to avoid over-plotting misinterpretation

[cmdcolin]

#4647 introduced alpha transparency related to modification rendering.

low quality positions can be plotted with alpha transparency. however, if you are zoomed out far, many low quality positions can basically overlap, resulting in the alpha values overlapping, which may give the impression of a high quality call. turning the rgba(x,y,z,a) into a "equivalently lightened" rgb(x',y',z') without alpha channel might help