As with driving a car or riding a bike at night, compressing and diffusing the light horizontally makes more practical sense to me.
I’ve tried looking for solutions and the closest seems to be these diffusers for bike lights.
https://www.amazon.com/gp/product/B00RKP6GZG/
https://www.amazon.com/gp/product/B004WLCLQY/
Technically speaking, these are more like anamorphic “lenses” for lights.
Size wise, they come in only 39mm and are too big to be “pasted” directly on the front glass of my dive lights (Sofirn SD02 and SD03).
Of course, if I can fashion a holder to hold it further away, this should work.
If anyone has suggestions for a holder or other sources that provide smaller diffusers, that will be great.