So my personal process on large throws starts with a note that I only load large throw rounds in smaller batches, and I'm not running in hurry up mode while I do it. That said, I like to not trust throwing a double charge so I invested in a Hornady Auto Charge.
Now. For consideration is that the Hornady Auto Charge, does speed up the process, but is maybe not what I would call "100 percent trust worthy". Like, it seems to fudge the numbers a bit sometimes. not significantly to where there would ever be safety issues, but .1 or .2 gr difference can affect point of aim, FPS, etc and I mess up enough shots on my own without help already.
So what I do is with this, and any other auto that I've used, I set it up side by side with what I call my "scale of record" which ultimately is the scale, out of the few that I have, whose measurement is my golden standard for what I am weighing.
Sidebar: I check my scales against each other from time to time and they're reliable, but I just count that a single scale is my master. So if I write down load notes, the charge going in the book is the one from that scale so that if there's every any deviation, I can work it out and adjust accordingly)
Anyways, back to the throw. With the two side by side, I'll turn the hornady on with the pan and zero it. Then I move the pan to the scale of record and zero it. I set the Hornady to throw .2gr below what I actually want. So if I want 70.4gr then I set the hornady to throw 70.2. With the charge in the pan (calibrated between the scales) I move it to the scale of record and trickle the rest in to be exactly where I want it.
That might be slightly overkill, but it's my process to simplify the throw while making sure it's perfectly spot on to what I want. If I was throwing two charges and then putting them together I'd be weighing them all anyways.