advanced 3d carving on 4th axis rotary

[magicniner]

You can use an indexed 4th strategy rather than a rotary one, this will let you machine with the work fixed at multiple index angle intervals and access the entire part.
You can do this on a 3-axis system by having multiple copies of your part rotated in CAD to the required index angles and generating a path for each, paste the code together and manually add your index angles between blocks of code.
Ensure your clearance plane takes into account the rotating stock, it's easy to bust a cutter if the stock rotates and you haven't allowed for the corner height as it sweeps past! ;-)