SMOF_ — SMOF not a subset of UML

MOF is a subset /constrained version of UML now, as I understand it, but SMOF is not. MOF subsetting UML had many benefits, why not SMOF?

The constraint mechanism in SEMOF::Reflection needs to be revised to make SMOF a subset of UML. The classes SEMOF::Refelction::Compatibility and SEMOF::Reflection::Incompatibility shall be removed and replaced by a constraint carrying an OpaqueExpression with language = “SMOF” and the body holding the values “equivalent” and “disjoint”.
As a consequence of this change, regular UML tooling is sufficient to create and maintain SMOF metamodels, therefore the SMOF Profile is no longer needed and shall be removed.
SMOF reuses and completes the latent support for multiple classification and reclassification existing in UML. However, a more detailed description of the semantics and side effects of multiple and/or dynamic classification is needed.