So, in Fusion 360 I designed a dust shoe with a groove for inserting a length of brush on the bottom side. Looks good, perfect fit and so on. I exported the design to an STL file and brought it into CAMLAB and CAMLAB would not recognize the closed groove as a milling feature unless I used Relief cutting. So how do I get CAMLAB to recognize a groove as a grove for milling. A relief cut with a 1/4" end mill is ugly
You can create the gcode in Fusion 360 without using CAMLAB.
Did you actually create the groove on the bottom surface (as referenced in Fusion 360)? That surface would be against the waste board and inaccessible to the cutter. Maybe you flipped it in CAMLAB? Just wondering.
I find Fusion360 has a daunting learning curve for doing the G-Code; when I looked at that option, the tool orientation relative to the design and tool setup information required seemed a high hurdle. I am used to using it for 3d (additive) printing and this is my first effort at subtractive design.
I designed the plate so the bottom with the groove is oriented as the top (+Z) so the groove shows and this is how I placed it in CAMLAB. CAMLAB would only provide G-code to mill the groove if I selected Relief - and boy that groove came out bumpy from all the plunge cuts going in and out of the grove space from side to side on the X-axis 
In Rough or Finishing, it shows the groove in the model space but does not generate g-code for a groove cut at 1mm step down to 4mm total depth. Really weird.
I will keep trying though.
Thanks
Scott
Scott would you mind sharing a screenshot of your setup in CAMLab? If you’re willing to share the file I could also take the chance to set it up in CAMLab myself to see if I can replicate your issue
You are right about fusion 360 being daunting. Here’s the first of a series of lessons that I found very helpful.
Learn Fusion 360 or Die
https://www.bing.com/videos/search?q=fusion+360+or+die&docid=608045731102265203&mid=D55C86A28569577F3F71D55C86A28569577F3F71&view=detail&FORM=VIRE