IDM user move question

I'm hoping the knowledgeable people here can give me a bit of info around what I'm trying to do.

Based on the value of an attribute, I want to move a user account to a specific context. In addition to this, as a result of the move, I want to move their groupwise email account to a specific postoffice.

drivers in my setup include:
UserApp 3.0.1
Groupwise 3.5.3
eDir 3.5.1

My edir driver config is:
Publisher command transform
if class name equal "User"
and if source attribute 'Surname' equal "User" (so I only effect my test account)
and if operation equal "modify"
and if operation attribute 'Description' equal "USERS2"
and if destination DN not equal "TEST\USERS2"
move destination object (when="after, dn("TEST\USERS2"))
break

this seems to be working correctly, the user account is moved and all other associations are updated.

My GW drivers config is almost identical but it doesn't work:
Subscriber command transform
if classname equal "User"
and if source attribute 'Surname' equal "User" (so I only effect my test account)
and if operation equal "modify"
and if operation attribute 'Description' equal "USERS2"
and if source DN not equal "TEST\USERS2"
move destination object (when="after", dn ("TEST\RESOURCES\USERS2_POST"))
break

My questions are:
Should the above GW policy work?
Does the move need to occur after or can it occur during the operation?
Am I making this harder than it needs to be or is there a better way to do this?

TIA,
Ben.