One of the basic things about SciFlow is that it allows authors to write collaboratively. Users can write together in the same document at the same time, and even in the same chapter simultaneously. If you have questions about inviting co-authors or citing together, feel free to check out the two links.
It is possible to write in the same chapter of the same document or different chapters at the same time. You can create subheadings (H2-6) or new paragraphs (P) at the same time without issues.
That's it, you're ready to write together in SciFlow.