I have often found that adding an IFC reference into a model really slows things down. It's very annoying and makes it very difficult to work with IFC references.

This thread for example: https://communities.bentley.com/products/microstation/f/microstation-forum/238804/unable-to-open-import-attach-as-reference-some-ifc-models-with-connect-edition-17-10-17-01-58 where the user imports the IFC to convert it to DGN because it gives better performance when referencing ... It's a step that shouldn't be necessary.

When we look at any IFC viewer (BIMCollab Zoom, Solibri Anywhere, BIMVision, ...) they can handle large IFC files very easily even if the files are multiple gigabytes. When referencing an IFC file of only a couple hunderd megabytes Microstation already becomes very slow in comparison ...