Not yet, but when you have an instrument with such strong returns as TNA/TZA, switching 50% out of that instrument into an instrument that produces only half of the return cannot help the performance (drawdowns/risks put aside). Also, the definition of a good risk/reward balance is different for each investor.
So, as I wrote, new research results bring more questions, which lead to more research and so on.
I plan to wrap what I did up to now, write a report and then do more work on the pending issues.
Pascal