I've used ProGrids in several projects with good success to snap modular asset kits or place 3D prefab tiles on a square grid. However, with my newest project I found an opportunity for ProGrids to also support arbitrary grid types such as hex grids. Currently it is not really possible to snap to a hex grid, but it would probably be relatively easy to let users configure the snap increment value for each axis separately, which would then allow snapping to any type of grid, including hex tile grids. For example, I would like to configure the snap increment for the x-axis to 0.9 and for the z-axis to 1.57, this would solve many placement issues even for special use-cases like snapping to non-square shaped modular kits. This feature would probably be best disabled by default, but a configurable setting in the user preferences.