Does every new idea need an immediate practical use?
Ideas that aren't ready to pitch need somewhere to live where an unfinished thought won't be mistaken for a commitment. A clearly labeled idea notebook or an agreed team space works. Say up front that entries are exploratory, with no delivery promise attached.
The imagination session made room for ideas that didn't fit an existing category. In an organization, that kind of exploring only works if people know a note is just a note.
Leave colleagues' names off an idea unless they've accepted the work. For each one, jot down the part you want to investigate and the question that makes it interesting. You don't need a market forecast to justify keeping a note.
Deciding comes at a different time
Pick a separate moment to choose which ideas deserve development. That's when you look at audience and feasibility, and at what it would cost. Keeping the stages apart lets you be generous while you explore and disciplined once resources are involved.
I'd also think about where the notebook lives. A private idea can still contain material that doesn't belong in a new tool, so respect confidentiality and ownership. The space gives you room to explore, and the responsibilities that come with the source material stay in place.
What to try this week
Start the notebook with a header that says entries are exploratory. Then add one idea, with just the question that makes it interesting.