Slow it down way to fast for that material. Need to increase the depth of cut to .75 at least. Here is what what HSMAdvisor came up with from the Helical Website's speeds and feeds for this tool. Here is a good link from their website about how to know what a tool is doing. 8 Ways you're killing your endmill

Another option is the Sky Hook, I believe they are in Idaho. https://skyhook.cc/

I recently read the Multiaxis Essentials training tutorial again. I found an error in the tutorial#1. My tutorial is the 2017 version. I'm not sure the new version still includes the same tutorial#1. This error is in example 2 -machine the conical helix. the conical helix example still use the same line in the cylindrical helix. this is the error I mentioned. actually conical helix line is shorter than cylindrical helix line. the cylindrical helix length is 26.38inches, the conical helix length is 23.4 inches. see the attached drawing

Well... at least he's got some maximum material condition to work with. @BBprecise, are you probing with G68.2 active?