I am currently using the combo in the title and without the TC 1.4x, the module used is Sony + Canon 400mm f/2.8, which is great to enhance sharpness on my pictures.
I really would like to enhance sharpness on pictures shot with SEL TC 1.4 and would like to know if you are going to support it ?
I have exactly the same problem, there is no optics module for the FE 2.8 / 400GM lens and this lens has been on the market for almost four years. I don’t understand how it’s possible! At FE 4/600GM, even with 1.4TC/2.0TC, modules are already available, but FE 2.8/400GM is still ignored.