After seeing what that MCEX16 can do, I am tempted to pick one up (the GAS is starting again).
I actually enjoy how it helps to enhance the bokeh of an image, but I'm wondering if it will work well for portraits. I've seen a video of something using it with the xf50-140mm and it was very impressive.
Extension tubes really bring you in to the subject super close and work best for a poor man’s macro setup.
Here’s a chart from Fuji on minimum and maximum focusing distances with both the MCEX16 and MCEX 11.