So I have a custom GP tool, takes an input FC, does some stuff (Calculate coordinates a bunch of different ways/formats). Want to share it to a standalone server (10.7.1) from Pro 2.4 (but I think an ArcMap answer will work here). When publishing, complains about blah blah blah is not registered (the input layer) and will be copied to the server. In the Pro sharing dialogue I see
But what I want is for the user to pick whatever fc they want, not the FC I used to generate the GP History item (needed to publish). I vaguely recall being able to do this with %scratch% and model builder (https://enterprise.arcgis.com/en/server/latest/publish-services/windows/gp-service-step-by-step-watershed.htm) but a solution to my issue doesn't manifest itself from that tutorial (which BTW needs to be updated to the Pro workflow).
https://pro.arcgis.com/en/pro-app/help/analysis/geoprocessing/share-analysis/quick-tour-of-authoring-and-sharing-geoprocessing-services.htm seems to suggest that I have no choice but either copy the data, or reference a datastore. Am I attempting to do something with sharing a custom GP that isn't possible? Sure would like to get all my GP's converted to services.