Yes that may work and solves the visual part of the problem, but not the general performance problem. I worry that in the step file Data model the object is still present. My experience with 3D and Performance is that it does not so much matter how the object geometrie looks geometry, the count of objects/elements matters more.
A good example that explains the problem is a 500 Pin BGA, when you look at this in the 3D PCB view you only see a Square with a height, very simple looking nothing fancy. If you now export this Board with only this BGA on the board, the export can take very long.
The reason for that are the 500 Pins that are also going to be exported to the step file, every ball is a element and gets exported.
To round it out: The count of Elements matters, only export what you need is key to performance here.
This is just my opinion and is based on my experience.
But yes this is a workarround that can help many ppl,cgood you found it.