Thanks for the context, @meg_watt
In the interim, I’d recommend leveraging Bluescape’s comments feature to create a dialogue among groups. 
If you want to encourage a general dialogue, my recommendation is to create a canvas for the group/project/initiative, and add comments to the canvas, which acts as a “container” to hold all related objects to the project within. Example below:
Note that you can also use comments on other individual assets, not just canvases. You can keep comments focused on one object such as a text box, shape, notecard, video or image.
See example below - when commenting on an image, the pixel where you commented is remembered:
All comments in the workspace can be accessed from the :comments: (comments) button in the top right of your workspace.
Here are some resources to help you get familiar with the comments feature: