Korean Air’s SKYPASS program has announced that effective July 1st 2020 free stopovers on award tickets will no longer be permitted. The July 1st, 2020 is the flight date, rather than the booking by date which is sometimes the case. Currently you’re allowed one stop over in each direction. It looks like you’ll still be able to do stop overs with other SkyTeam members, but those flights are subject to a separate award chart and must be round trip.
Hat tip to Traveling For Miles