Anyone using Canon 8-15 With Sony / Seacam rig?

I am using a somewhat dated (very dated?) Sony A7R III / Seacam rig and after seeing the success some members are having with the Canon 8-15 I'm considering giving it a try. I was particularly intrigued by this thread where @jjmochi described using the 8-15 with a 2X TC to have a zoomable +/- 15-30mm. I'm wondering if anyone is using the 8-15mm with the 2X TC in a Seacam housing with a Seacam SD dome port. I use the Sony 28mm / Fisheye Converter in my current rig and it's a fine setup, but I'm looking for the versatility of a zoom if possible.