Here is another tweak I made to use in conjuction with repair time tweak:
Basic.cfg-
[DAMAGE]
OpenComp=1
PartiallyOpenComp=0.8
EnclosedComp=0.5
I increased the enclosed and partially enclosed compartment numbers. This way, personell and equipment inside the sub are more vulnerable to damage and death (creating more need for repairs and such) before hull integrity reaches zero. Makes for some serious Das Boot moments. 