My galaxy brain moment was realizing that there’s nothing special about a “manifest file”. It’s a technique, not a file type. It can be in any format you like, containing whatever data you like. The point is that it’s a mechanism for storing data, reusable across many fixlets.
After experiments with data formats, I’ve settled on JSON for manifest files, and a glorious one-prefetch-block-to-rule-them-all. (Currently in testing.)
It will save massive amounts of tedious work in maintaining changes for products that change frequently, and customer-site fixlets that must be changed in lockstep.