Back-faces option for Polygon node
The polygon node seems to have just 2 options for top/bottom cap. That seems redundant to me when it could just have a back-faces toggle instead which would halve the vert/tri count when you want both sides. If I specifically wanted a top and bottom cap, couldn't I just use an extrude node with a very tiny height, top/bottom caps enabled, and sides disabled?
In fact, now that I think about it harder, wouldn't it even be more efficient for me to use an extrude node with only a top cap and enable back faces on that?
Anyway, it seems like polygon should have a back faces option, even just for consistency with other nodes.
If you enable backfaces on a polygon, you have the same triangle/vert count as having a top and bottom cap. But you are right - having a backface option would be more consistent than a bottom cap option. The Polygon, Extrude and Lathe nodes are all really just PlanSweeps with constraints. The Polygon node is a PlanSweep sides turned off. It was created before the backface option was added to all the Meshers.