Recently, I tried RhinoInsideRevit a bit. I found that RIR has this Direct Shape to help deliver geometry from Rhino/Grasshopper to Revit.
I would like to note down some thought I currently have while I developing alongside.
According to the RevitAPI doc page about DirectShape:
https://www.revitapidocs.com/2022/bfbd137b-c2c2-71bb-6f4a-992d0dcf6ea8.htm
This class is used to store externally created geometric shapes. Primary intended use is for importing shapes from other data formats such as IFC or STEP. A DirectShape object may be assigned a category. That will affect how that object is displayed in Revit.
So, which may mean that although RhinoInsideRevit might be a get-around solution without producing/ exporting a IFC file by building the Rhino on Revit (In runtime, Revit occupied some memories, and inside those memeories Rhino takes some part to be built), internally, both (IFC-way and RIR) use this DirectShape to help external geometry to be put inside Reivt.
About what RhinoInsideRevit, we can refer this QA interview video from the official developers group.
https://www.youtube.com/watch?v=kckMA-GdsLc&t=6451s