I think it's common... TTL mode has been miss more then hit for me. I do also find it giving me more light then needed. Check with a friend and the saying is that it's better to shoot in manual.
With regards to things happening really fast. Then it's a matter of knowing the strobe and distance from subject. Plus. Doing test shots.. Esp for wide angle. For Marco.. Usually have more time...
Fortunately You need to turn it a bit more than 1/4 turn to flood the camera. During my first dive I turn it almost 1 turn when I realized that there is something wrong. Then I try silver tape - doesn't work to keep it. With this port as the user of aqupazza I already decided that I have to forgot about exchange lenses underwater. Especially If I have Inon UWLH100 plus Dome unit, which is quite heavy and it is a bit difficult to unscrew the lens with one hand and try to keep port with second one. I did this few times, just to flood the space between lens and housing, but now I am doing that on land, before diving, and feel much more comfortable, without stress
i myself also hate screwing the lens in and out... i think i have the best solution... i find from this company..