Something that I do from time to time is re-template a project if significant revisions have occurred while working on it. The easiest way to do this should be to simply copy and paste the project back into the template section and remove the old one. However, this carries the "done" state as well.
Currently, the Alt-d shortcut does not toggle. This means there is no way to cancel the done state of something from the keyboard. Likewise the contextual menu is no help here either, so there is no way to perform this action on more than one task at a time with the mouse either. It appears the only way to actually reset a group of actions is to go down the list, one by one, and manually click that little checkbox.
There are two things that could make re-templating easier:
1. Improve the keyboard access here so that an entire project can be selected and reset at once. This would also include extending the Alt-d shortcut to setting the completion/uncompletion state of projects too (something that should probably be fixed anyway).
2. Stuff getting pasted into templates loses its completion state. Arguably, there is no use for having stuff in templates that is completed anyway, the whole project, sub-projects, and actions should be reset.
In my opinion, #1 ought to be addressed anyway, because that impacts normal workflow from time to time. Granted it's generally not very annoying as usually I unmark things as done fairly rarely---but it does happen. It just bit me today though, when I re-templated a project that has about a dozen sub-projects and 60 actions. That took a lot of clicking.