Hey @shedev,
Theoretically, you could disable all fields on the form if someone else is editing it. See if this helps: RealTime Data List In PLumsail Form - #2 by mnikitina
Coauthoring is a different story though, it's much more complicated. You can drop us a paid support request at support@plumsail.com, and we'll see if it's possible to implement the feature for you.