Inconsitent handling of tiny structures

[rennne]

When I use " 0.15mm OPTIMAL MK3" with "detect thin wall" very tiny walls are extruded but not slightly bigger structures.

First a very tiny wall is taken into account:

The same object with a much bigger wall, but the wall is now ignored:

I found that this tends to happens when the two sides of the little wall are not perfectly parallel.

The two stl files:
boxAandB.zip

[tecnopolis-ve]

I've been struggling with the same behavior, try to disable "detect thin wall perimeter"

[rennne]

When I disable "detect thin wall perimeter", it just get worse:
Both structures are just ignored.

In all cases the egde is more round then a normal 90° corner, but when no wall can be applied it at least should be sharper, like a 110° degree corner and positioned more outside-> in the direction where the missing structure should be

[supermerill]

it's a known issue, i try to resolve it. See slic3r/Slic3r#4534 and https://github.com/supermerill/Slic3r/wiki/thin-wall-improvement.