This kind of may be related to viewtopic.php?f=23&t=7978
which I posted a few days ago.
In my opinion I would not say that there is definite need for an extra perimeter at all.
Basically S3D just does not know (at least seems not to) where the underneath infill walls are
and hence where there is no infill prints the top layers in midair.
Using the S3D support you will just get advised to increase infill percentage and toplayers
which I think should not be the solution at all.
For what can those values be adjusted when there is always need to keep them at a kind of high-level.
For more than a year know I have been sitting in front of my printer for hours and days watching my things printed
and feel convinced to recognize and determine one slicer from the other just by watching how a slicer does handle certain things.
It would be great (S3D already is) it could cope with top layers the same as e.g. the Makerware could.
For the above mentioned problems it would be enough to remember where the infill walls are and treat
the 1st toplayer as a bridge from infill-wall to infill-wall just the way the makerware does.
I used a screenshot of your attachment to make a "drawing" to show how the Makerware does.
Don`t anybody tell me this is about saving material.
Having to use a high infill-percentage where there is no need most certainly needs
more material than bridging with the 1st top-layer...