iPhone 12 camera on swimming fish from riverbank

I’m thinking of upgrading from my iPhone 8 to an iPhone 12 Pro. One of the less talked about uses in reviews is underwater footage while standing on a riverbank, particularly at night. I use a handheld focus adjustable torch for primary illumination. My iPhone 8 gets video, that even at 3 meters distance allows you to see fish or eels, so I can try and engage my kids with the natural environment, the fauna, in the places we visit, even if they are reluctant to get up or go out with me.

So my question is - does the lidar-assisted autofocus, with optical zoom, on the iPhone 12 allow me to potentially capture better footage? Would the river surface be the focal point, so eg. Fish 30cm below the surface might be blurry? And are there video and still camera capture modes that allow me to disable the lidar if it’s interfering with the quality through adjusting the focus?

I’d like to use any new phone at sea as well, capturing fish, sea plants and coral, below but near the surface, while the water is relatively still. Both at night and in daylight with the sun reflecting off the waves, taken from out of the water, is it likely that the footage would be of reasonable quality - potentially enough to identify species later?

I’d love to hear from people who have tested their lidar-enabled phone in these use cases.