After setting VKFFT_MAX_FFT_DIMENSIONS there's an error error: array subscript 2 is above array bounds of ‘int [2]’ [-Werror=array-bounds=] (it's a warning converted to an error by -Werror).
Used VkFFT defines:
VKFFT_BACKEND=3
VKFFT_MAX_FFT_DIMENSIONS=2
Attached a patch (diffed with develop branch: e8e6a39) that fixes the problem. However I've tested only with the above defines, and I assume it may not fix all problems.
VKFFT_MAX_FFT_DIMENSIONS.patch