This should be easy enough to reproduce:
- Note the tool configured for Outline ops (enabled or not)
- Set up a Contour operation to use a different size tool & enable the Contour op
- Slice
- See that the Contour operation used the tool configured for Outline ops.
- Select different tools in the Outline configuration, reslice for each & see that the Contour operation always uses the Outline tool
The trivial workaround is awareness of the unexpected behavior.