We use the pro_format_dir for Formats and the start_model_dir for start parts and drawings templates. We have both of these setting point to Windchill folders which seems to work pretty well whether working in a workspace or offline from Windchill. Using Windchill also makes updating everyone's start parts easier than having local files. This will prompt them to sign into Windchill when starting Creo to be able to access the start parts/templates/formats but won't actually require them to be working in Windchill/Workspaces. You could always test changing the start_model_dir to a local folder and see what happens but I would guess it would still create local copies of the formats when working offline and not in a workspace. If users are working offline in Windows folder, they may have to replace the locally copied formats when then bring the CAD back into a workspace. Another trick might be to add all the desired formats to their workspaces from Windchill before importing their CAD/drawings into the workspace but I haven't tried this. Putting the Templates in the start_model_dir also has the benefit of making your templates show up in the New Drawing dialogue box.
We started using Windchill Projects to avoid teams manually share CAD with jump drives or network drives. This works best when you have multiple people trying to access the same CAD during development and don't necessary want development CAD in the PDM system. Took a little bit of work to get the Project settings working correctly but it seems to have been worth the effort.
The first part of the solution is to set the directories (PRO_FORMAT_DIR, ETC..) to a Windchill location in your config file. We have them set in the config.sup so it is harder to change.
The second part of the solution is to connect to Windchill, but do not activate the server so inside Server Management it looks like this:
