Problem with Minifig Head Pattern

[Christian Neumann]

hi,
i have run into problems while finishing a minifig head pattern. when i take a look at the result in ldview (quality mode), usually the edges with conditional lines are smoothed out, but not this time. the overall look is some kind of "ok", but there are several regions that look strange.

here is what i did:
1. created flat pattern
2. sliced with slicer pro, then optimized the result manually (e.g. re-triangulation with new vertices)
3. projected with slicer pro onto former shape
4. to get rid of some rounding errors (0.00000001), i used former shape as subpart in shaped pattern, and snapped on it with unificator
5. checked with planarcheck, found no problems
6. created conditional lines with edger2

however, the result is not satisfying me. i tried with several different thresholds and precision settings, but i don't know exactly at which point the problem occurs. maybe someone can give me a hint what to do?

here is a screenshot of what i'm talking about:



i discovered this in some other minifig heads, but there must be 1) a reason for this, and 2) a solution how to avoid it?
any help is appreciated.

greetings,
christian