Better Hexagonal Tiles
This is a simple module for FoundryVTT that adjusts the rendering position of Tiles on hexagonal grids.
Most hexagonal assets come centered inside of a square image, for example:
FoundryVTT's Tile renders assumes that the hexagon is as close to the top left of the image as possible. This makes it look like FoundryVTT isn't snapping Tiles to a hexagonal grid correctly.
Without Better Hexagonal Tiles
Note that in this image, the hexagon appears off center.
With Better Hexagonal Tiles
Now the hexagon looks much more natural.