YES this is possible.
In JMS 1.1.x, if you want to create
www.master.com/slave1, you have to create the directory slave1 with a SSH connection or FTP tool or whatever tools that awill allow you reate the directory.
Once the directory is present , you can configure JMS to deploy the slave site into {root}/slave2
In JMS 1.2.x, you just have to click the check box to request create the directory when it is not present. In this case, it is no more require to create the directory before deploying the slave site.
At the origin the "deploy folder" was design to allow deploy website into a directory created by the hosting server tool (CPanel, Plesk, ...).
Therefore until JMS 1.2.x that now give the opportunity to create the directory, it was request that the directory is present before deploy a slave site into a specific directory.