The CPU usage seems fairly high so probably one of the objects you are using is very CPU intensive. You could try to add --high-performance-mode
to the "custom command line options" in the Bela IDE. At that point the IDE may become unresponsive and you will probably have to stop the program tapping briefly the button on the Bela cape and wait a few seconds for the IDE to become responsive again. You could also increase the block size to gain some extra CPU time.
Why are you using PureData for this, by the way? Could you not do this directly in csound? That would be lighter on the CPU, especially because you would get even more benefits from increasing the blocks size (using Pd caps those benefits).