Good question on tools improving collaboration.
I like the work that Philippe has done with the spreadsheet and I think that using the Github issues will be quite helpful.
There are two areas I find challenging in collaborating on the model.
One is tools. I would like to re-use the work Phillippe, William and others have done to offer improvements to the model, but I haven’t found a way to import the XMI documents. I have tried using GenMyModel, but the imported XMI document just shows up blank. This is likely my inexperience with the tool, but it is a challenge.
Another area is understanding the changes changes to the model. For example, the model diverged from SPDX with some recent changes, but I wasn’t able to find out why the changes were made. This will be partially helped by tracking issues in Github. Another way this could be improved is adding commit history with granular changes and summary comments. If the tools allowed for it, we could even open it up to Github pull requests where anyone could submit the changes in addition to submitting the issues.