I don’t know whether this idea has already been proposed in the past, but looking at the site carefully, I don’t thinks so.
For each sub-site (like Stack Overflow, Cross Validated, etc.) you have a unique section where users can post questions and receive answers. Do you think it could be a good idea to add a section (like Cross Validated Research Area, or Mathematics Stack Exchange Research Area) where users can post their research and findings instead of posting questions only? That is an area where users can post answers to unsolicited questions that they ask themselves and have a relevance to subjects in the corresponding area.
This is already a wonderful place where to exchange ideas and knowledge. But maybe that addition could have the potential to elevate it further and transform it into a place where people release their own research, or simply share some findings by writing short unsolicited articles for a potentially interested and specialized audience. That, for convenience, may be restricted to reputable users.