Fortifications

[Kiwikkiwik]

OK so
Explosive dust vision effects are already covered by dust/smoke in the game no need to add suppression for these any more than for a unit walking into a dust cloud from a clear hex.
Once out of the bunker your bunker vision issues no longer apply. so no need to add suppression for these either.
It only requires very light shelling to make the fortification suppressed enough to be useless, not heavy. And of course the vast proportion of shells would not land anywhere near the embrasure. have a look at the dispersion of a typical ww2 field piece. see figure 4 at
http://nigelef.tripod.com/errorsmistakes.htm
for example

Imp you say

The threat is over so would be unsuppressed as the bunker is likely to be.

The move after shelling stops, the bunkers is only -likely- to be unsuppressed if you are playing 100 morale units. if Your playing low morale troops the Bunker Suppression may last maybe 6 or 10 moves, depending. So the threat isn't likely to be over as soon as the shelling stops. not by a long shot

jp10 you say

they exit under fire or not under fire

Until the suppression is removed, they cannot exit -not under fire-. It might be 5 or 6 turns or more until the carried unit can exit -not under fire- ie with no suppression addition.

Imp there is nowhere in the help I can find where forts suppression diminishes any faster than any other units, nor can I find anywhere in help where a fortification gets less suppression than an infantry squad in the open, which makes me think the -shelter- bunker isn't particularly well named.