Convert SiriKit Custom Intents using non configurable parameters to AppIntents

I have an Intents definition file for a Custom Intent that I want to convert to an AppIntent.

The Custom Intent has the checkbox "Configurable in Shortcuts" not checked and therefore the "Convert to App Intent" Button is greyed out. I can however still do a conversion using the Menu-Item "Editor"->"Convert to App Intent". The intent has a number of parameters that are not configurable, but were set in code. This way it was possible to donate shortcuts with the parameters (and even the title) set in code. The automatic conversion using the menu item however produces a result that does not match the legacy Custom Intent (Parameters appear in the Shortcuts App etc). I also did not find any way to create AppIntents that have parameters that can be set in code, before the intent is donated.

I would leave the old legacy Custom Intents as they are, but as soon as make use of any of the new iOS 16 Shortcut features (App Shortcuts) the existing donated Custom Intents disappear in the Shortcuts App. Given the apparent inability to convert them into AppIntents due to the missing code-set parameters, I would be happy for any advice on potential solutions.