Unfortunately I'm not aware of anyone who has done a MS Project integration in a long time. There was an official adapter that was popular years ago but it was sunset as people moved towards Maximo specific tools for scheduling to have real time updates to the Maximo system. There are multiple solutions that I'm aware of and I'm sure there are plenty more that I'm not. IBM has Maximo Scheduler, Interpro has EZMaxPlanner, and Prometheus Group has Planning & Scheduling for Maximo (formerly Akwire).
I'm not familiar with the PTC Vuforia AR solutions so I'm not sure what functionality it provides and what it would take to integrate Maximo with it. There are IBM business partners for Maximo that also partner with PTC which I'd expect to have better answers but I'm not sure how open they would be to sharing that information to a non-customer.
IBM Maximo Mobile provides AR functionality in the Assist product for having an expert assist in the execution of the work where they can mark up and provide detailed instructions for the technician. Then as other users have similar issues/questions the information from that session is available for them to refer to. If that's their primary use case I'd probably have them evaluate the Maximo Mobile solution as well. I'm pretty confident we wouldn't support HoloLens today though.