Just to confirm, Trainz will error check against all installed mesh-library library revisions starting from the revision specified in the mesh-asset tag.
So if the mesh-asset tag specifies <kuid:648132:100797>, but the mesh being specified is only present in <kuid2:648132:100797:1>, then it will show an error if <kuid:648132:100797> is also installed. As such if you are specifying a new mesh added in an update to the mesh-library, you should specify that revision of the mesh-library in the mesh-asset tag.