Quick update. So I removed a disk by 1) removing its disk path under Disk Management, 2) taking the drive offline, 3) putting the new drive online, mounting it to the original folder, 4) remove old drive in DrivePool, add the new drive, 5) update snapraid.conf, 6) running SnapRAID to repopulate the new drive, 7) run rebalance in DrivePool so everything shows up correctly.
I looked under Balancing again, but this time instead of losing all of the File Placement settings, it retains it but as noted before, I specified one folder in the pool to use only one drive. My setup for testing consists of two drives. Here it ends up selecting both drives to place the data on, so technically the settings are not retained.
Also, under File Placement, if I click on Rules, an error window pops up: "Can't cancel task. The given key was not present in the directory." And this error pops up again when I click back on Folders.