I doubt FTM will change their import. As well as not handling the Source on a Note FTM doesn't recognise the other Note type entries such as Census and Diary - it just throws them away with no error message.
I can use the Delete/Change fields option of Generations to convert them all to Misc Notes but then they all become one Note in Generations and it doesn't help address the Source issue which is my main concern.
If only Convert to Fact took the Source with it !!