Handling of slot attribute is not done correctly

I use SLOT attribute in the driver element to reference an speficic version instead of using main (default one), but when I start up the JBoss the attribute is erased and it uses always the .jar file inside the main folder.
I tested deleting the main folder, so as to be sure the JBoss was using my .jar inside the slot folder, but it doesn't work.
From looking into code, functionality is partly there but it does not work as it should.