[libgdx] PolygonSpriteBatch draw outline of map tiles

Hey.

I’m new to libgdx.
Im rendering a hexagonal map, so i have a polygonspritebatch and a polygonregion (which describes one hexagon).
In the render loop i iterate through all of the map hexagons and render the polygonregion for that tile.

Now i want to draw the border of some of this hexagons. I first thought to use a shaperenderer - but the problem is,
then i have to iterate through all of the map objects again, because before i call begin i have to call end on the polygonspritebatch.

And, furthermore, shaperenderer was actually implemented for debugging purposes.

So, is there a way to draw a NOT-filled polygon with polygonspritebatch?

Thank you!