You’re absolutely right that a blunted edge on the tool will make any issue with the toolpath worse. A cut with high vibration and chatter will also abuse the cutter and may well blunt it prematurely.
I’ve found in wood that I get a dark buildup when cutting woods with a high resin content such as maple which I can clean off with a tool cleaner or acetone. As for sharpness Julien has some close up pics in the ebook showing the structure of the cutter edge and bevels which are linked in this thread
Since looking at those pics and inspecting some of my cutters under a proper magnifier I’ve learned what a new sharp and old blunt tool feel like to the thumb, at least for wood, still taking baby steps in aluminium.
Have you read gmack’s posts on feeds and speeds?
And yes, hopefully holgersindbaek will soon be finding a way to run that cut without problems, I’ll be interested to see what works.