Don't have any issue with the basic DIY approach. The size isn't necessarily a negative either as it's the same as another product touted for wedding photographers in another thread here. You'll just be very conspicuous. However, I'd be concerned that your setup is not exactly functional. Mounting for portrait orientation as you show does not appear to catch enough light from the narrow side of the flash tube. I think you are better off shooting landscape so you can mount the fan like a normal bounce card and tilt the head as necessary like others suggest. You can crop the image to portrait if you must, while your lighting will still be better. Secondly, the current way and limited angle will have different and possibly unwanted effects depending on your distance to the subject. I fear your use as fill light as shown will come out uneven or exacerbate face shadows.