Short answer is that - so long as you're disconnecting ALL of the drives in a pool - yes you can and it shouldn't cause any problems as far as DrivePool itself is concerned.
Slightly longer answer is that you would stop the StableBit DrivePool Service* while disconnecting/reconnecting, to avoid DrivePool briefly** complaining about missing drives and to avoid it potentially re-scanning the entire pool when the drives are reconnected, but the software is designed to "fail safely" so even that wouldn't be strictly necessary if you were ever in a rush.
Do make sure that all drives in the pool are set for "Quick removal": this should be the default for USB HDDs, and can be found in Windows Disk Management; right-click each disk in the pool - e.g. you'd click where it says "Disk 9" and not where it says "volume label xyz (drive letter)" - and then select Properties and then select the Policies tab.
*DrivePool basically operates on three layers: the file system driver (handles the low-level code that makes the pool visible as a drive to Windows), the drivepool service (handles all the balancing and maintenance), and the drivepool gui (lets the user see what's going on and create/configure/remove pools).
**if you disconnect all drives that form a pool, DrivePool will no longer know that pool exists until you reconnect at least one of those drives.
