The ACS is the ACS and before that it was the PTS, with the same tasks regarding high altitude operations. Been that way for years and years. There are pressurized aircraft that have a maximum altitude of 25,000, so that's where the commercial pilot with a wet ticket could take revenue passengers. No endorsement required. Additional training is required for above 25,000 and in the 135 world that is yearly for operators that go above 25,000.