If I slice Printable_Wrench_w_more_gap.A.0.stl from:
with slic3r default settings and:
--randomize_start --layer-height 0.25 --first-layer-height 0.25
I see a perimeter cutting a corner at Z=0.5mm:
Good catch, this is easily reproducible. After one hour of debugging, it turns out it's a Clipper bug.
Reported at https://sourceforge.net/p/polyclipping/bugs/92/
Debugging environment for issue #1834 about Clipper returning wrong d…
Upstream bug was fixed, but no new release is available.
I have the fix in my work tree, could generate pull request if you are interested ...
I don't feel comfortable using development version of Clipper... let's wait for the release.