We just upgraded to Odoo v15 Enterprise ed., primarily owing to the Gantt chart improvements.  Up until now, we have taken this approach:  

1. Create a quotation

2. Confirm the quotation to make a sales order

3. Go to the Project module where the sales order shows as a project with its (service) tasks.

This morning I followed the approach shown above and the Project tasks appear but not in the same order as on the quotation (this is for a construction contractor and the quotation list was largely in order of project implementation).  Also, in the quotation we created sections, such as 'Roofing' and listed all the tasks under that, that applied to roofing.  Of course, the section heading in the quotation don't show up in the Project.  I was thinking that, in Project, I could create a new task for the section headings and then link the other applicable tasks to that, as subtasks...but it doesn't work that way (the new section heading task invites you to enter new subtasks).

     I would appreciate recommendations from anyone that is well-versed with this to tell me how they approach it.  Would I have been better off 'starting' with the project, get it all organized and then transcribe (re-type) the tasks into the quotation?  In short, I'm looking for the benefit of your experience.