Hi,
I think this is really a question for the Fusion Forum.
When Fusion generates a toolpath it records and tabulates the path in its own proprietary fashion. Only when a post is applied does that proprietary tabulation
get converted to Gcode. Therefore the post must use Fusion's tabulation methods, something that Artsoft cannot do and possibly would be illegal to do even if
they could do it. In effect all Fusion posts are written and maintained by Autodesk
I don't know if you have had a close look at the (Fusion) code that constitutes the post. Almost ALL Fusion posts assume a four and/or five axis machine, commonly however
the four and five axis functionality is turned off so that it produces regular three axis Gcode. With a few keystrokes you can edit the post to turn that functionality on. I suspect by:
"var useInverseTimeFeed = true" to "var useInverseTimeFeed = false"
effectively demands a full blown, ie five axis post.
In any event I think your enquiry should be on the Fusion Forum, and if I'm not mistaken there is a whole board devoted to Fusion posts.
Craig