I know at times there is situations and out of the need we must use other tools for what they were intended for while yet keeping in mind their design and cutting properties.
I have on several occasions setup a larger 2 to 2.5 dia spade drill and designed them as a from tool and cut on a Wire EDM to the profile I needed to produce.
I used a 3 degree draft and depending on the complexity of the profile I would alternate sided of the cutter into the tight areas to provide clearance.
After cutting the profile one would have to finish hand grind relief as you can imagine the amount of relief needed for something with that thickness.
I would rough out the pocket or exterior and then interpolate the profile that was required.
I found it did require additional time to indicate the spade drill to ensure it was sitting properly so both side of the spade drill form tool ended with the proper form.
When I get a chance I will post an example of a design.