Comment 2 for bug 1641419

@Udi - What do you think about adding a progress bar between uploading the JSON file and showing the list of nodes in the register modal? Also, I've added a scroll bar in the design in the case that there are a large number of nodes. I made sure to note that this should only scroll in the left panel so that the user will always be able to see the node detais on the right:
https://lizsurette.github.io/OpenStack-Design/tripleo-ui/3-tripleo-ui-edge-cases/21.registerlargenumbernodes