Hey Phil!
Thank you for the wait.
The cause of that error is the result of objects being too big to fit in the data section. You can try moving some of the stuff to SDRAM.
Our guess is that the fftInstance is the really big thing that should be moved.
So, arm_rfft_fast_instance_f32 DSY_SDRAM_BSS fftInstance; to move that object to the SDRAM.
Also, new is not typically used in embedded in our experience and will require some refactoring to use the SDRAM. Therefore, everywhere you reference it needs to be changed to &fftInstance.
We hope this helps!!