Typically with CMB to USA fares, an extended transit (<48 hours) in HKG is available on the return for a very very small surcharge. In some cases, as a result of a disconnect with the HKG-CMB leg. And yes, many of the fare classes have a specific no stopover clause on the outbound legs. I would maintain the minor extra amounts I have paid the TA in Colombo are well worth the money as she provides excellent response times. But sometimes fare rules and point of sale defeat her. Note that UL R class fares credit 100% to Asia Miles.

Also note that PEY fares exJNB to the USA are almost enough less than exCMB to pay for a Y round trip CMB-JNB. Assuming you have the time and inclination to make the detour... A question under consideration if this can be done before 16 April.

Happy wandering

Fred