Simultaneous editing is definitely the right approach here. Collaboration tools need to become more realtime and synchronous. However, the devil is in the details. If everyone is jamming together, then it’s all good. But the key here is how the system resolves conflicts. Otherwise you might end up with endless “Undo” wars between strong-willed, opinionated designers.
How does Figma handle such conflicts, Evan Wallace? Does the owner/creator of the project have ultimate say? Can he or she lock down certain features or parts of the design and declare them to be done? I suspect much can be learned from the way Wikipedia handles edit wars. Realtime collaboration doesn’t mean everyone has an equal say. Someone still needs to own the project and resolve differences of opinion.