I don't think there is an existing approach for this, but the community would certainly benefit were there a nice way to share them. In the past I ran into some some collections of set definition files via Merlot and a quick search quickly found an example https://www.merlot.org/merlot/viewMaterial.htm?id=1377405 .
I would think that collecting the set definition files in GitHub (in a different repository than the main OPL) and maybe making a Merlot record might be better than providing a static zip file. Such a new GitHub repository could provide a simple home for collections of textbook/topic groups of set definition files.
If you are willing to take part in starting a project to share such collections of set definition files, I would recommend contacting Danny Glin and Marianna Bonanome to ask they can help create some infrastructure to work in.
Some quick thoughts:
- Maybe have the first level directory be the textbook name, the second for the "contributor" (so if multiple people want to provide sets for a given textbook they will be easily distinguished).
- Inside the second level folder put a README file and the actual set definition files with names which indicate what section they belong to. (As necessary use some additional directory levels).