Completing last task of a project deletes the project

Is there a way to change the setting for multiple projects at a time to convert them from marked as done with last action to ‘manually’ mark as done despite there being no action left to do in the project ?

I just did a little experimenting, and what I could do was to go into the Projects perspective and choose View > Collapse All so that I have a list of projects. Then I could highlight the projects I wanted to change and then check or un-check the “Complete with last action” box for all of them. EXCEPT: the “Complete with last action” box is not available if a project is set up as a “Single Actions” project, and so if the group of projects you have selected contains even one Single Actions project, then the checkbox will not be active when the group of projects is selected. So it seems like if you want to do this, you need to make sure that all of the projects you have selected are either Parallel or Sequential. Fortunately there is an icon next to the project title that shows what “flavor” of project it is, so that you can de-select any Single Action projects so that the “Complete with last action” box will be active for you.