Agreed! And in cases where the convolution kernel (bokeh, but in frequency space) is something more complicated than gaussian, FFT can definitely be a very good

Agreed! And in cases where the convolution kernel (bokeh, but in frequency space) is something more complicated than gaussian, FFT can definitely be a very good option (kernel/bokeh-res can be near-ish to the res of the image-to-convolve, for example, and full-colour kernels/bokehs too).