Well I did a feature request for integration of technology similar to VST Connect and VST Performer into Dorico Pro (VST Connect and Performer), Elements (only VST Performer) and SE (only VST Performer) which will allow people to instantly collaborate over internet. The feature request is here:
Until then you could collaborate by sharing Flows which can be Exported and Imported into the very same project. Probably this will be the fastest way?!