Well, I appreciate the comparison to those much more expensive software packages

. For what a 1-year subscription costs for Maya or 3ds Max -- $1470 USD (!) -- you could buy more than 20 copies of Magic Performer (and own them forever, not just 1 year).
...but seriously. When you say "capture the visuals", I assume you mean exporting them to a movie file? If so, there are a few things to understand when comparing Magic to Maya, etc.
First, Magic is optimized for real-time rendering, meaning WYSIWYG -- what you see is what you get. You get the actual final rendering even while you are editing the project, and never anything less than the final rendering. This is very different than those other programs, which are focused on exporting movies "offline", rather than letting you see the final result in real-time --
especially at 60 fps. Magic relies almost entirely on the GPU, and surprising though it may be, it is highly inefficient to get a rendered image back from the GPU into main memory. So it actually takes longer to export content to a movie than it does to just display the content on the screen.
Second, and more importantly, many of Magic's visual effects and audio analysis techniques are very sequential in nature, meaning that rendered frames depend heavily on previously rendered frames. It is therefore nearly impossible to do anything in parallel, which is what multithreading would achieve. Further, GPU-based rendering does not support multithreading well -- it's just not how graphics acceleration works. You can search the web for any number of pages that say this. Here's one of the first results:
http://stackoverflow.com/questions/1109 ... -on-opengl. To summarize, the GPU takes care of multithreading
inside itself, meaning there is lots of parallelism happening in each frame, but only between different pixels in one frame at a time. Between different frames, there is not much that can be done. By contrast, in Maya or 3ds Max, the final rendering usually does not use the GPU (exclusively), mostly the CPU, so it is much more parallelizable.
Finally, and most importantly, I think your main bottleneck is this: because you are exporting from Magic in 4K, you are required to use the .png export format, since .mp4 doesn't support 4K. It is *much* slower to export to .png, because it uses lossless compression, and the files are much larger. But, unfortunately, you don't have a choice. This is partly our fault -- we haven't provided any alternative export options. But we will
So, to answer your overall question, yes, Magic does support multithreading, to the extent that it's possible. All the graphics rendering happens on one thread only, but other things happen in other threads.