if you don't have duplicate data on that drive you should could estimate the remaining time with the used space on the drive. all files should be moved to the other drives. at the end it should be nearly empty.
maybe you should have a look into the windows task manager or resource monitor how fast the drive is reading data.
So far this beta is not working on so many levels.
It is hard to build up a Pool, when you can't select your drives. Before I was using TrueCrypt Volumes. Now I decrypted everything and using the drives directly with Drive Bender (2x3TB). But still I couldn't add a second drive to my pool. Had to create the pool with the stable version and upgrade then. Even with the Console it was not possible to add drives to the pool.
First I had 1,2TB of data on one Disk. Then the balancing was running and it was shifting more than 50% of the whole data to the second drive. I aborted the task an deactivated the balancing feature.
Then it shows sometimes around 1TB of non pool used data. I was moving every data into the pool. Didn't just convert the drive into the pool. Now it is still showing 2,4GB. In my mind it should be zero.
Now I got a problem with Origin from EA. This software is not able to create folders and files in my Pool. When I change the Game Folder to my System drive it is working.
I'm going back now to version 220.127.116.11
I know this is a beta version, but I'm still a bit disappointed, that some core functions are not working any more.
Hope version 2 gets stable soon.
Edit 23. dez 20:20
Now I reverted back to stable 18.104.22.168 and Origin is working again and can create folders and files in the pool.