Required reintegration
Required reintegration of any improvement is a feature of free software (where it applies to copyright only) and Consortium licensed deliverables (where it also often applies to patent and even trademark).
Open source does not require it at all, and shared source often requires ceding all rights to the original vendor on very limited terms.
Consumerium License will almost certainly have to have this clause. There may be variant conditions under which reintegration is required, which might be factionally defined. This is possible only with a parametric license.