Fixes for error occured after publication of 2.0.0

[axtimhaus]

Unfortunately, right after publication of 2.0.0 errors occurred while publishing plugins.

• Spreading using equivalent width reversal did not work.
• Heavily overfilled grooves without spreading model.

Reason was the no longer cleared, but reevaluated, cache since 8ca461b. Fixed with this PR alongside with some related refactorings.