I took my new Canon R5 out over the weekend to practice. I used my Sigma 150-600 Sports lens along with the 2X extention. I used different shutter speeds, Apertures, and ISOs. Here are a few of my shots.
the blue one is perfect, just a bit to much negative space in the upper part, but might be perfect for some slogan then...
Yes. It will also AF using the 2X extention. The only problem I have is that the minimum aperture is 10 or 11 the extension.