@ShaunP so, the way Evolve works when the Local Storage extension is used in a SCORM course is that it tracks the data twice over: saving data to the LMS as it normally would - but also saves a more comprehensive version of tracking data to Local Storage.
When the course is next launched it will try to load data from Local Storage first but, if there’s nothing there, it willl use the data from the LMS as a fallback.
I’ve just tested this myself in SCORM Cloud by launching a course with Local Storage enabled in Chrome, working part of the way through it, closing the course, switching to a different browser and launching the course again - all components I’d previously completed still showed as completed and the bookmarking dialog took me back to the last completed component.
I guess one possible issue is if the support agent has previously run that same course on behalf of a different user they could have Local Storage data stored from that session which won’t match that of the user they are logged in as. To avoid that possibility they should either do a complete ‘Delete browsing data’ before launching the course - or start the course in Incognito/Private browsing mode.