It was quite a journey from a simple cross-compiled Darwin output to a lengthly chain of operations and changes on a Mac until I got a signed installer that passed notarization and gets accepted by Application Loader.
Now four hours have passed, and the build I uploaded using Application Loader still didn't appear in App Store Connect.
Details shown before upload were correct (Bundle ID, SKU, Apple-ID). If I try to upload it again, Application Loader now tells me a binary with the same version number was already uploaded. Still, App Store Connect doesn't show a single uploaded build.
Does anyone have any experience how long it takes between successful submission with Application Loader, and the build appearing in App Store Connect?
("Solution": a mail in the spam folder telling me that another Info.plist field was missing. Would've expected results to show in the App Loader or the web interface - my fault
)