[Warner306]

I followed the guide and have everything set up and working fine, except for one thing: when watching 1080i content using forced film mode/IVTC, Kodi is not switching my output refresh rate to 24p, as MPC-HC/MadVR does when watching same content. It stays in 60p.

Any suggestions on how to deal with this?

Try enabling refresh rate switching in madVR. That way, both Kodi and madVR would be set to switch to the correct resolution.

You might want to contribute debug logs if this behavior is bothersome. Instructions on how to do so are provided in the last section of the guide. It sounds like something that should be fixed. However, there are a couple of other bugs that are getting priority right now.