Okay so I moved the path to Contents/Helpers. I tested in a Virtual Machine (though not a complete fresh one) but it seems the services for the app in Contents/Helpers are indeed discoverable.
So over the last 8 years I either misremembered my reason for choosing Contents/Applications/ or I made a mistake or this was an issue that was resolved during that time. In any case I think the complete answer is:
Use Contents/Helpers instead of Contents/Applications to get the app out of the Spotlight app launcher on Tahoe. Thanks for your help
Topic:
UI Frameworks
SubTopic:
AppKit
Tags: