When modelling a floor shape sometime it is neccessary to trim the end off beams to form the correct angle.
When using the tool "Opening by Face" tool to perform this task yo will get the following warning.
Opening partially cuts host.
When you have dozens of beams per floor on a complex form this can result in hundreds of warning for something is really not an issue.
I would like to suggest that Revit need not be concerned whether the opening fully or partially cuts the host.
Regards
Jim Wright