When the object we iterate over is not part of the depsgraph, we cannot get the evaluated copy to export. This workaround is temporary to avoid a BLI_assert() failure getting the evaluated mesh of this object. This will be handled more elegantly in the new AbstractHierarchyIterator that I'm working on, but that requires a bigger change than we should allow this close to the 2.80 release candidate. This fixes a problem described in T58686.