Tamron 35mm f2.8 macro for E mount - anyone using underwater?

This strikes me as a good general purpose lens, and good for a little light duty close-up work.

It is keenly priced (c. AUD 350).

Minimum focus is 15cm (1:2 mag), which makes it OK to use smaller domes (eg. 140) to calm the aberrations.

Land reviews praise its sharpness, and criticise its AF as slow (a bit faster in AFC cf AFS).

There is no other close-focusing AF option around 35mm focal length for Sony shooters, but Canon makes an R series 35mm macro.

So, is there any Sony shooter out there using it underwater, and if so how do you find the AF (especially in low light); and are you using a dome?

Thanks in anticipation...