Please make the "merge without review" NOT on the screen that renders all the changes

We had quite an update on one of our libs. That concluded changes on several hundert elements. When then trying to setup the merge with our main file, there comes the
“Pulling it all together” window which stayed open for more than an hour.

That would kill the whole branching feature for us if that takes so long to display - cause I can only merge without review after all the changes are being rendered on that window.