I don't understand what it means (and that page doesn't explain) for a 'constraint' not to be enforced? Do you somehow get some sort of warning, but not an error, i.e. the insert/update is allowed to work, everything proceeds as normal, but it's there to check on and correct if you want?
Note Snowflake supports defining and maintaining constraints, but does not enforce them, except for NOT NULL constraints, which are always enforced.