Hi, I've managed to get this working using the UC function approach. The key is to have a good detailed description on the registered function and then a detailed instruction in the genie room itself. For my test I used a UC function that was calling the Azure dev ops API. In your example you could put something like the following as the comment on the UC function:

'Use this function to search the web for real-time information.
  Call this when the user asks about current events, latest trends,
  recent news, or anything not available in the taxi trip data.
  Example questions: "What are the latest AI trends in 2026?",
  "What is the current weather in NYC?", "Search the web for recent taxi regulation changes'

And then in the Genie Space instructions:

 "When a user asks about information not available in the trips table, such as current events, news, or web searches, call the function workspace.default.search_web_research with their query as the parameter."

You need to do this as Genie will always prioritize using the tables you've added. The prompt will force it to look at the function for particular things. I hope this helps. 
The only other thing is you need to make sure the users of the Genie space have access to the UC function. I'd test that the Genie Space works in the normal workspace before then testing it in Databricks one.

Thanks,

Emma