In a case, I asked a fact-checking for some statement, and prompted "use Ukrainian keywords for the research". Merling did the fact-checking properly but ignored my in-prompt language preference and showed me Hungarian (my language) articles.
For this multi-language research, it's a key that we use the proper language pool for searching for the information, and Merlin should bridge the language gap. :) (A miracle that has never been existed in human history before.)
Best!