I’m not sure what you mean by a funding pipeline, and I guess how many ZIPs depends on what Shielded Labs is planning.
The most minimal thing I can think of wouldn’t have any deposits, so if only that were deployed, the net effect would be to just smooth issuance to a decay curve (and remove halvings). I would guess that could be a single ZIP.
One kind of deposit that seems simple and safe to me is a rule like “90% of txn fees are deposited into the fund and 10% go to miners”. We want some to go to miners so they have an incentive to include txns. I don’t believe this would be controversial for miners since fees are so tiny today, yet that also means deposits would be small. Meanwhile it gets the ball rolling so that if fees go up (say from more adoption, ZIP-317, ZSAs, etc…) after this change were made everything the Sustainability Fund would start working it’s magic. If we waited until after fees grew large and then attempted to redirect them into deposits, it may be more controversial / political at that time.
I personally would advocate putting that kind of fee change in a separate ZIP from the basic Sustainability Fund definition. It’s conceivable some would want the SF but not that specific fee change, and even if everyone wants both it feels cleaner/more modular and establishes a precedent for “here’s how to introduce SF deposits in a ZIP” for any future protocol changes (e.g. ZSAs, bridging, programmability, …).