Flat-shaded faces exported as smooth-shaded

[irisnotaprogrammer]

All of the normals and UV-map settings seem to not appear to influence the Smooth Flat setting or adhere to smoothing settings.
This issue appears sort of or might be similar to issue #10 .
Models appear with smoothing errors like in the screenshot:

Steps to Reproduce

Exporting any Blend file with the appropriate material settings (in my case a baked texture), any normal and UV-maps setting.
No error messages.
Attached blend file of the model used to test:
Tarwestraat_Gymzaal_nr1_Github.zip
Texture belonging to the model:
Tarwestraat_Gymzaal_nr1_2048x2048.zip

Version Information

• Blender versions tested: 3.3.1, 3.5 and 3.6.1 (I started with this, not seeing in time it's not officially supported, which is why I tried the other 2).
• Exporter: Version used as linked in issue Ability to export with custom split normals #10 Ability to export with custom split normals #10 (comment)

Note:
I have messed with the source code and removed the transform module in the exporter. This has solved the smoothing problem, but I will add I have no clue what this might do for animations and their origin points. It was merely a try at attempting to solve this specific problem because for now, it would make my workflow A LOT quicker instead of going from 3.x.x to .obj, import it in 2.79b, export to .x and from there with the XConv tool to .o3d.
For me removing the transform settings and conversion don´t really matter right now: given Blender's design methods, it's good practice to keep transforms in an end product at 1 by definition which is something I do regardless of designing for OMSI.

[Road-hog123]

I'm not sure why the test version doesn't fix this issue, but there's a good reason it's still a test version... when a fix for #10 does make it to a release it will also fix this issue.

For now, as your object has no curved surfaces, you can use an Edge Split Modifier to produce the desired result with the current release version of the exporter.

[Road-hog123]

Duplicate of #10

[Road-hog123]

Reopening until I have a unit test that proves this is fixed.