I think you could check real time YM charts, when trading the DBF or CFD, for your real time analysis and decision to go long or short. I know, the problem is real time CBOT data for the YM is needed and not free. With all CBOT data you can have data for US treasuries: This is not the thread for that, but this is (slow and predictable and) great to day trade.
Also and more importantly, US treasuries are full of good information if you like to study correlations.
At first, you could manually backtest for few weeks / months on (free) delayed YM charts and see for yourself if you can find an edge or if your decisions would have been different.
I know, we don't see the same patterns on charts and more importantly we don't react the same way. But if this "reverse analysis" helps and if it is free, why not give it a try?
Best!