That means starting data from manuals showing H870 or AA8700.
I haven't run the Hornady bullet but would not hesitate to ask them if they have start data for their bullet.
Failing this, I would suggest being careful and use a Dacron filler if you download since ignition can become erratic with a low case fill.
In QL, we used H870 data to get rolling and went from there, but you will expect to see slower results till you get rolling with your batch.
I don't personally mix or blend powder batches. In my experience, the ES/SD of non-blended powder is better so I load at the range and adjust the recipe in real-time.