Take the following case in which some vertices are weighted in full 1.0 (RED), some have a weight of 0.0 (Blue) and some are weighted very close to full (0.9) and some are weighted very close to zero (0.1)

In this case it is very hard to visualize which vertices are weighted 0.0 or 1.0 or which are just very close but might have a different influence.

For that reason we have a Zero Weights overlay that uses black to indicate 0.0 weights

With this overlay enabled it is quite easy to distinguish between 0.0 or just very close to 0.0

What's missing is the same logic but for values of 1.0 where an overlay would show the Full Weights in white, 0.0 in black and the rest in the typical colors

Note: The above screenshot assumes the implementation of another related task