It would be great if when you click on the window's title bar the options would be displayed at the top and you could drag it to where you want it to go. Samsung's Easy Desk does this and it's pretty cool and quick. It basically has shadow boxes ( half and half, third and 2 thirds, etc...)
Greetings, Thank you for posting on Parallels Forum. We've forwarded your request to the respective team for further discussion. We don't know when and if it will be implemented, but in any case - we will let you know. Should you have any additional questions, let us know. Have a great week ahead!