The HM MUST communicate the effective Level of Assurance of the combined assertions. The effective Level of assurance is the minimum of the LoA of the Authentication assertion and (if applicable) the LoA of the Representation authorization assertion(s).
The MR communicates two Levels of Assurance in its Assertion. A LevelOfAssurance (requested) and a LevelOfAssuranceUsed (actually obtained). The HM MUST use the LevelOfAssuranceUsed from the MR Assertion as the LoA of the Representation authorization.