Revit 2023 IfcExportAs and Type parameter ignored

In Revit 2023 there are new builtin IFC export parameters introduced.
Most can be easily updated with API or dynamo, however instance IfcExportAs in Groups can't be automatically updated.
For example, some rooms / area's need to be excluded from a IFC, now we do this by means of a KeySchedule (quick and reliable) and API based on workset visibility.

As now the IfcExportAs is completely ignored by the IFC exporter all of these need to be transferred to the new builtin ones, which causes some problems.
In short, this is more timeconsuming and loss of accuracy (all instances need have to be filled in manually, and not just once!)
- Keyschedules no longer usefull
- Global parameter can't be used

We would like to see that if the buildin IFC parameters aren't set, and there's a IfcExportAs parameter with value that this is used.

Minimal:
Instance builtin parameters:
- Export to IFC => this can be used as is, By Type / Yes / No
- Export to IFC as => if empty and above is Yes then see if there's a instance IfcExportAs and use that.
- IFC Predefined Type => same behaviour as above, use IfcExportType when empty.

Other options are that Revit 2023 allows the builtin IFC parameters to be included in KeySchedules or by global parameter and/or option to make the instance onces group independent. (same issue with the IfcGuid, which is not group independent)

Start by locating the C# IFC exporter logic that reads Revit's built-in IFC parameters and the legacy IfcExportAs, then trace how grouped instances are handled. Compare the requested fallback behavior for Export to IFC, Export to IFC as, and IFC Predefined Type with the existing parameter flow. Done means unset built-in parameters consistently fall back to the legacy values without breaking explicit built-in settings.

Written by the indexing model from the issue text.