After testing the SONY FE 24-70mm f/4 ZA OSS extensively (I did over 200 dives with this lens already), I have to say - it's a pretty good setup for Lembeh! It gives me the flexibility of shooting a wide range of subjects and I'm not stuck with a macro or a wide-angle setup. I can shoot critters that are very small - I cannot fill the frame with a hairy shrimp, but when using an extra macro wet-lens (like the SubSee +5 or Nauticam SMC), I can fill the frame with subjects the size of around 1-2cm (around 1/2 inch) in Super35 mode. When shooting in full frame mode @24mm I get vignetting from the flat port, but I can shoot at the 32mm range of the lens without vignetting and shoot subjects the size of around 30 cm (1 foot) right in front of the port (I'm using a Subal Type4 flat port on a Nauticam NA-A7II housing with a Nauticam to Subal adapter).
I used the Nauticam SMC only for subjects smaller than 3cm (1 inch), for subjects between 3-8cm (1-3 inches) I used the SubSee +5 and everything larger than 8cm (3 inches) I was able to shoot without having to add an extra wet-lens.
Here are some example shots:
The 24-70 is very sharp - even at smaller apertures.
Here are some Lightroom screenshots:
Coconut Octopus (Amphioctopus marginatus) @42mm, f14, 1/60sec, ISO250
Same image like above at 100%
Here's a shot @31mm - on the top left the port is still visible, that's why in full frame mode the lens has to be at @32mm (at least with my setup)
Here's a short video shot with the A7R2 and the SONY FE 24-70mm f/4, for best viewing experience watch in 4K:
When shooting video I also use the Clear Image Zoom function of the A7R II - then I can shoot very small stuff like the Costasiella kuroshimae, also known as the "Shaun the sheep nudi" with the 24-70mm lens (with an additional Nauticam SMC) and I can fill the frame @70mm in Super35 mode with subjects smaller than 1cm in size - pretty amazing! :-)
Don't get me wrong, I still use other lenses and the 90mm macro is a "must have" lens in Lembeh, but the 24-70 is also a very nice lens for shooting macro and even super macro in the Lembeh Strait (when combined with a flat port).
This test was done while diving with Critters@Lembeh Resort.