You need a consistent exposure (or well working bilagrid) if you want to train more than SH0. For SH0, I think its more important to get the poses right than to have consistent exposure.

Funnily enough I tried to scan the engine room of a lifeboat using an old school original osmo, quite possibly darker lighting. It worked, but had too many motion blur frames to be of any use. But I did fix the the shutter speed to an average. Like to say, too much dynamic range to work well, but it think a consistent exposure is import

I did not set any shutterspeed. In environments of high dynamic range you cannot create a splat at a fixed brightness setting. However, this one was especially bad, because frames of a video do not contain exif data so the adaption in post isnt well possible.

What shutter speed/iso did you have to use in the end?