I often load files from Dropbox and it’s no different than working and saving to my computer. Your connection speed may be different.
The way I work with my (1) SU colleague is we date every file in the name. Might work on one date for awhile but it gives an idea what version it is. Some interim or exploratory work may be initialed by one of us( in the file name)–then we choose which file to go forward with.
Another method is to leave the master file in the server and work on components saved from the master (contextual menu “Sava As”) that you can reload to the master file as needed. Then you can work on different parts of the project without affecting the other’s work. There is also an extension by TIG that mimics XREFs in AutoCAD.