I downloaded a hip made by @mikelyndon-sesi, then I add a vertex animation textures node to do a quick test.
In houdini 17.5.264, Game Development Toolset 1.165, the BBOX MAX 1 and BBOX MIN 1 are always 0, even I put the ground plane lower than 0.

Below from houdini 17.0.506, Game Development Toolset 1.165,

I downloaded a hip made by @mikelyndon-sesi, then I add a vertex animation textures node to do a quick test.
In houdini 17.5.264, Game Development Toolset 1.165, the BBOX MAX 1 and BBOX MIN 1 are always 0, even I put the ground plane lower than 0.

Below from houdini 17.0.506, Game Development Toolset 1.165,
