So i was thinking instead of  a smoke bomb you could produce a smoke screen out your funnels that would block sight and hinder the accuracy adjustment as smoke bombs do know,
To counter this problem you would have to move a scout to the other side of the smoke screen.
The smoke screen could last for ten sec then slowly disappear.
The smoke could have a cannister or bar that would give you a gauge of how much oil you have left to produce smoke, this could work the same as smoke bombs and a bomb would be a cannister that could last for 3 sec.
I think this would work well because as you rush the smoke is behind you and  isn't effective but as you turn and retreat it masks you.

As for submarines they could retain the smoke bombs.
I belive they did have a form of smoke bomb but they were made using toxic chemicals that would be hazards to the crew but as a sub this wouldnt effect them.

Look forward to hearing some variations on this idea.
I found this website on WW2 smoke screens
p://www.wwiismokescreen.com/history