Unsure about the pre-release timing, but the latest stable release is where Drying and Printing can happen at the same time.
While drying, I can start a print job, which will Load the filament to the nozzle, finish the print job and Unload the filament back to the AMS.
But, while drying, when I click the Load or Unload button in the device tab, I get an error message that the printing is busy drying.
This is a little disconnect in the firmware.