Would be great, especially for big projects to have ability of sharing one project between more designers to let them work on it at the same time. For example we have specialist for EM and outside illumination, but they have to wait until the main building illumination is done (we are often requested to have everything in one output only, mainly for presentation purposes to demonstrate 3D vizualization). But there are many other reasons why this would be great (if you need partial help, if you are under time pressure and need to speed it up, etc.)

Put the evo file on cloud sems not be a solution, as only one designer could work at a time.