min / max corners for 8 cubes forming a single cube around an origin

This would be a lot simpler with vector arithmetic, but we can do it with the raw coordinates:

mins_0 = Vector3(org.x - thick, org.y - thick, org.z - thick)
maxs_0 = Vector3(org.x,         org.y,         org.z)

mins_1 = Vector3(org.x - thick, org.y - thick, org.z)
maxs_1 = Vector3(org.x,         org.y,         org.z + thick)

mins_2 = Vector3(org.x - thick, org.y,         org.z - thick)
maxs_2 = Vector3(org.x,         org.y + thick, org.z)

mins_3 = Vector3(org.x - thick, org.y,         org.z)
maxs_3 = Vector3(org.x,         org.y + thick, org.z + thick)

mins_4 = Vector3(org.x,         org.y - thick, org.z - thick)
maxs_4 = Vector3(org.x + thick, org.y,         org.z)

mins_5 = Vector3(org.x,         org.y - thick, org.z)
maxs_5 = Vector3(org.x + thick, org.y,         org.z + thick)

mins_6 = Vector3(org.x,         org.y,         org.z - thick)
maxs_6 = Vector3(org.x + thick, org.y + thick, org.z)

mins_7 = Vector3(org.x,         org.y,         org.z)
maxs_7 = Vector3(org.x + thick, org.y + thick, org.z + thick)