happy to help when I can, as this site and its members have helped me quite a bit with numerous things. Stumbled on the MGI calculator when searching “overlap calculator” a while back.
You mentioning overlap got me thinking. I find interesting the -1 degree overlap result.. @ .050" I can see it is correct. However, overlap at .006" is 58 degrees!
It can be seen on the graph.
-1 degrees is really deceiving. This cam has significant overlap. This is a good example of why specs are important, and also why we should check them at multiple lift points to get the whole story. I suspect its also why different cam companies list specs at different lift points .006" .009", .050" etc.. They don't want us comparing other companies cams to theirs on an equal basis. They know it gets so confusing that most people will just stick with one manufacture because they understand how the specs worked in their last build.
If you look at the graph you have hella overlap from .006" lift to maybe about .040". This must be what creates the "thump" aspect..