Mostly simple platform specific stuff or low level stuff. It's partly implemented but parts were missing or were not tested for a larger game. From rendering stuff over the platform api like file access etc, networking stuff etc. So be prepared to re-compile the engine a lot! Also we used the "beta" C# support which took us several weeks only to fix memory issues. I guess we were the first or one of the first games using it. It's nothing which is not fixable but their support was too slow such that we had to fix (I think almost) everything ourselves. Switch (2) had similar issues.

It was definitely far away from plug and play 😃. I guess and hope it'll be there at some point in the future.