Cutting and pasting activities from one schedule to another

There doesn't appear to be a way to cut and paste activities from one P6 schedule to another. The only way I've found to do this is to export the activities as "Spreadsheet (XLS)" from one schedule and then import them into the other schedule.

In P3, you can open two schedules at one time and cut and paste activities from one to another.

I believe there are existing enhancement requests to give P6 the ability to open two schedules at one time, switch from one schedule to the other, and to be able to close one schedule at a time and not "Close A