Hot adding DS14MK4 trays to existing loop

This is something I've never had reason to attempt until now.

We have a 3270 cluster (8.1.2) Head 2 aggr1 consists of these two multipathed DS14MK4 trays (IDs 1,2):

http://i.imgur.com/821iN35.jpg

We want to hot add another DS14MK4 trays racked right above (IDs 3,4):

http://imgur.com/FlMxpyz

I've read the 2011 DS14MK4 guide and verified the loop speeds are all set consistently and IDs are all unique. (note: trays IDs are 1-4 from bottom to top)

Can I simply:

1 - remove the top two pairs of fiber and transceivers (these go to head 1 (partner)) 2 - daisy chain up from those vacated ports to new trays (3,4) 3 - plug the fiber and tranceivers back in on the top tray?

We would then grow (effectively double) this aggr1's capacity

What are the risks ? (2011 guide mentions panic's are possible with loop misconfig)

(we have 60 VMs running on head 2 on a separate loop and aggregate)

Any other tips appreciated

thanks