PR: Some elements weird export behavior

### Problem Description

Hello there we have found out that some elements are exported differently than others, despite fact that these are the same type in Revit.

We have Custom IFC 4x3 setup including "Revit property sets".

After export it seems that some elements keep all Psets and other do not.
In example "C-shaped" roof has all Psets and Parameters

Smaller roof on the other hand has not all of those

Examined this even further in BonsaiBIM and found out strange thing.
"C-Shaped" roof is an IfcRoof class with geometry and all parameters

Smaller roof is exported as 2 entities IfcRoof with all parameters, but no geometry + IfcSlab.ROOF with geometry but not all parameters....

Found in Revit 2024, tested in 2026 same issue, in both versions:
- IFC 2x3 - seems fine
- IFC 4 - seems fine
- IFC 4x3 - not fine :(

RVT + IFC there
[NotExportingAllParameters.zip](https://github.com/user-attachments/files/20604517/NotExportingAllParameters.zip)

### Revit Version

2026.0.x

### IFC for Revit Addon Version

26.1.0

### Windows Version

11 24H2

Start with the attached NotExportingAllParameters.zip and reproduce the export in Revit 2024 or 2026. Compare IFC 2x3, IFC 4, and IFC 4x3 in BonsaiBIM, focusing on the smaller roof being split between an IfcRoof without geometry and an IfcSlab.ROOF without all property sets. Done means IFC 4x3 exports the roof geometry and parameters consistently.

Written by the indexing model from the issue text.