There are always feature requests for various features and improvements to widgets which Jules understandably will never have time to fully address given the size and scope that JUCE has grown to.
How about taking a bunch of these Component objects (TabbedButtonBar and TabbedComponent immediately come to mind), moving them into their own separate module, and publishing them separately under a dual MIT / GPL license? There could be significant benefit: these objects would be developed in parallel by users. JUCE could still be sold under the commercial license. It would be optional whether or not Jules wants to pull some subset of the contributed changes back into JUCE.
This wouldn’t affect sales of the commercial JUCE license since its only a subset, you would still need to purchase a license in order to ship a proprietary application. And, since this separate module would be MIT licensed, JUCE licensees could use it in their proprietary software.