Disclaimer: I'm no machinist.
I've been using adaptive tool paths for milling aluminum for quite a while with generally good results. I have, however, noticed that tools tend to break at the end of a profiling operation and I have not been able to diagnose the issue. I've tried different feed rates, tool speeds and stepovers to no effect. It always occurs at the end of the pass as the tool begins to enter the previously cut region. I'm not running a proper mill, just a CNC router, albeit a fairly rigid, all metal machine; nonetheless, it could still be a rigidity issue, but wanted to check with experts.