The path-metric-optimize-includes and path-metric-optimize-excludes identities have been defined with the base path-metric-type in RFC8776 in order to be used within grouping optimization-metric-entry
With the current definition it is also possible to use them as path-metric-bound as well as path-properties. However, it is not fully clear how they can be used in these two cases
Note: they could also be used as tiebreaker-type but this depends on the resolution of issue #263