thank you Johnny, much appreciated! I had spent all day replanning the trip and searching for availability on other airlines to swap the sequence of two cities, so now, have the side effect of being able to visit Medellin which I hadn't planned originally - planned an alternate itinerary in case the certificate became an issue: USA->Bogota->Medellin->Lima->USA. Your feedback and data points are very helpful - I have tickets on hold for both itineraries (USA->Lima->Bogota->USA; USA->Bogota->Medellin->Lima->USA), so I will sleep on it and decide on one after I get approval from work to take time off.
Really appreciate your help on this!