There is a lot of stress inflicted on the lead kite's stock framing once the stack gets larger. You might consider beefing it up.clickable thumbnail
I have run into that issue with my TRLBY stack. Did not have a special frame or bridle for the lead kite of just six & the bottom of the lead kite would deform when the spine bent. I replaced the spine with a carbon reinforced tube of considerable strength. Had to ream the fitting a bit but that was the only issue.
Have the TRLBY stack up to nine now with no further issues. I remember the old Dynakite site showing a metal ghost frame available to act as the stiff frame needed for the twelve stacks. I have doubled up bridles on some stacks to get more bridle strength where I did not have heavier bridle line on hand. I found out the there are variations in bridles from otherwise seemingly identical factory made kites. Currently stacking some Revolution Sportwings, 1.5's. They have the famously interchangeable frames so that will be helpful. Shouldn't be too hard too come up with beefier rods for the little Micron. Any suggestions? SHBKF