Once you get into that 4th axis world, things tend to get really expensive, really quick.
I've helped myself around that with coding my own tools, mainly by parsing G-code and transposing one axis to another, which isn't that difficult to do once you get it. Yet, that isn't where I want to be in the long run. I've done some other crazy stuff so far with open source CAD/CAM software such as the cat shelf line, that was a lot of extra work which could have probably avoided by using more professional tools.
The other main thing I wanted was to be able to do was to extend the capabilities of the chosen software to do what I want to do, as in add-ons.
Vectric Aspire 8.5 does all that, so I placed my order.
Stay tuned, I'll let you know how it works out - first up is to adapt the Vectric stock PostProcessor to the Momus and implement that 4th Axis at the same time.