From: Hex 82,170
Looks like michaelm did some checking magic and has some island size defaults running against stacking limits. Only looked at a limited set, but in that set found very small islands that would spec out to 30,000 troops (or more) based on their terrain and modifiers under the SL calculations, that stay as 6,000 under the "very small" island paradigm.
Will have to do a poopload more checking, but looks like michaelm, once again, has proactively saved us from a Folie à deux.
Well, it is my understanding that, if an island hex has both an "original" island-size stacking limit, and a "new" stacking limit, then the most restrictive limit should be the one that is applied. So, for example, very small islands should always be limited to a stacking limit of 6,000, regardless of terrain type.
At least I hope that is how the code works! I have not tested it.