This is indeed an issue that occurs more frequently with X-mount and esp. combined with the larger/heavier lenses. We've had it several times on various X-Ts and only the X-H1 is really better (and the GFX). Make sure that when they tighten the screws they put a drop of Loctite on the tip of the screw. That really helps.
Sports Finder crops the display by 1.25x, "reducing the picture by an amount equivalent to increasing lens focal length by 1.25x" ... says the user manual. I assume this means the 23mm lens effectively becomes 34.5mm (in full frame 35mm format). The Digital Tele-Converter on the other hand gives an equivalent to either 50mm or 70mm. Is Sports Finder therefore just another digital tele-converter, or is it doing something else entirely?
I now know the reason for the "shake" the mounting plate on the back of the camera is a little loose. I will return it to the shop and give them the option to tighten the screws as I don't have the apropriate tools.
I ordered my lens from the Pergear because it has discount when I bought it. And I use it most the time with my X-T4.
The aperture can be adjusted by turning the aperture knob at the bottom of the lens to A. You can use your favorite aperture adjustment method according to your preference.
Build quality is really good. The lens hood is made from metal. It's small and lightweight.
Love my new lens.