The Fill Tool would be more useful if it used Point Thickness to Detect Gaps.

Shown below is a common occurrence when drawing by hand. I'll have two strokes that visually overlap, but when I use the fill tool, the material leaks out because there's a gap between the actual points. I could solve this by upping the leak size, but that comes with the drawback of getting poor coverage on sharp corners. Ultimately, when I have a fill leaking out, I'm forced to comb through the drawing in wireframe, searching for any gaps, and patching them manually.

A possible solution I thought of would be a setting on the fill tool that tells it to look at the end points of each stroke, and see whether their thickness encompasses the points of another stroke. If another stroke's points are within the "thickness radius", it'll bridge them so that the fill material can't leak out.