Terrain Splatmap leaking?

Hi,

I haven’t submitted it as a bug since it may be wanted behavior, but…
if I destroy a terrain, the “splat alphamap” stays in memory. If I destroy several terrains, Unity crashes. Is there a way to destroy the alphamap, too?

It doesn’t matter if I destroy the terrain via GameObject.Destroy() in playmode or just remove it from the scene in the editor. …

Same issue here in Unity 5.5.4. Anybody solved this issue yet?