I like the idea and would like to make it possible.
On the implementation side: I don’t think it will be necessary to integrate this tool into an issue tracker or software forge.
A website could be created where a maintainer could list the feature requests and required commissions ajnd link to them from the relevant issues.
This approach is independent of the software forge and could be integrated using their APIs. And it could very quickly be prototyped.
See: socialcoding