If this is already a thing I am unable to find it, could some kind person point me to it? 
If this is not currently a thing, it would be handy having a toggle to invert the selection for the shell function. I find that I spend a lot of time selecting all of the segments only to leave out the 1 I need to create a shell, would be super cool to just select that one segment from the beginning and click invert.
Hi!
A workaround would be to select the whole body (either using area selection, double click/tapping the body, or using the items list), and then deselect the one face you don’t need (a single tap with pencil, or SHIFT+Click with pointer).
So basically, instead of trying to leave out one thing, select everything, then remove the one you don’t need
I hope it helps.
I gave it a try but it appears that if I double click for select all to the body then click shell then de-select a face the shell operation is cancelled. If I first select shell then try to select faces I am not able to select more than one at a time. I figure I am goofing up a simple step here lol
It depends on the shape, but shell might not be available, as in some cases it cannot produce a valid body.
You are right, shell tool doesn’t have area selection activated yet, sorry I forgot.
Ah ok, I tried this on a box and it works exactly as you described.
I have a cylinder with an extrusion on an end and some rounded edges and this technique does not work, however if I click shell and manually select all but one face it does complete the operation.