Does anyone have much experience with active storage pools?

My current customer isn’t allowed to reclaim tapes, so their inventory of 
primary storage volumes is much larger than their ATL. This makes client 
restores prone to failure because of the number of primary volumes that need 
manual intervention as well as the lack of routine operational support at the 
site. 

I’m considering creating an active storage pool. Once fully populated, its 
tapes would remain in the ATL; mere primary volumes would be on-site but not in 
the ATL. I know I can start to create it by defining an active data pool to be 
written to as primary tapes are being written to (we already use this for copy 
volumes), but there’s still the matter of copying into the active pool the 
active data on the existing primary storage volumes. Is there any way to build 
the active storage pool in phases, such as “all the data that’s four weeks old 
or younger” or “all the data on volumes that are available; don’t flinch at 
volumes that don’t mount”? Otherwise, the COPY ACTIVEDATA process is going to 
run 24x7 for a long, long time. If I cancel an COPY ACTIVEDATA command and then 
start a new one, does it correctly understand what it no longer has to copy? 

Do reclaims of active data storage pools rely upon EXPIRE INVENTORY running 
regularly? We haven’t been running EXPIRE INVENTORY out of an abundance of 
caution to avoid any risk that we lose track of an inactive object someone 
might demand from us, but I suspect we’ll need EXPIRE INVENTORY to keep the 
active pool correctly populated. I can imagine how to set the retention 
policies to mimic not running EXPIRE INVENTORY, but that still might make Some 
People nervous. 

Thanks to Wanda’s tip about EXPORT NODE a couple of weeks ago, I think I know 
how large (roughly) my active data pool would be if I create it and populate 
it. 

What am I forgetting? Is my plan fatally flawed? 

TSM Server 6.3.4, if it matters.

Thanks,
Nick