Lazy brush paints too often

**ArmorPaint version:**
ArmorPaint.org - v0.8 (2021-04-27) - e334850

**OS/device including version:**
Win 10 x64

**Issue description:**
Lazy brushes paint too often

**Steps to reproduce:**
1. Build a brush like this one. The key thing is the random angle here
2. Use the brush an get sometimes "crosses" and sometimes not. I would not expect this result but maybe it is unavoidable?

Also when creating a random radius the brush changes its radius in a high frequency. I see why this is the case but I'm not 100% sure whether this is desired or not. To reproduce build something like

On the other hand painting with a brush like that is just cool. I really like the radius animation.

No source file, test, or entry point is identified in the report. Reproduce the random-angle and random-radius lazy-brush behavior using the linked brush setups, then define done as consistent handling of the reported paint frequency without losing the desired radius animation.

Written by the indexing model from the issue text.