Dyron Wide angle correctors for m43?

I came across a store review of the WWL-1 and an interesting piece of glass showed up there: the Dyron SWAL13.

Has anyone tried this, and its narrower siblings on a m43 camera?

First round I'd try it on my NA-RX100iv for 4k video shooting, as a cheap alternative to the WWL-1.

I have had a Dyron SWAL13 for a few months now and have used it on a few different California trips. I am pretty happy with the results so far. (Disclaimer: This is the only wide angle lens I have ever shot with). I am shooting with a Canon G7X and Nauticam Housing (w/ Short Port). I have not shot any video with it, only stills.

Here are a few SWAL13 shots:

http://jonjake.com/files/2016/11/IMG_2917.jpg (no cropping)

http://jonjake.com/files/2016/11/IMG_2875.jpg (cropped)

http://jonjake.com/files/2016/11/IMG_2004.jpg (cropped)