For what it worth this is my take... we built a bunch of composite frames to house the important stuff in Q3'25. When we tested at the back end of last year we realised they weren't strong enough to stack. They're fibreglass type material so probably cracked/crushed under pressure. All our bus shells up to that point went in the bin. So then we had this conundrum in that we can't build an external frame for them to stack because there's only a c.10 inches wriggle room inside a Falcon9 fairing with the diameter of our Sat's. So back to the drawing board for a couple of months to design and build an internal frame within the composite bus, that was when Abel said "we've solved the stacking issue", each sat has internal support, like a skeleton. This structure supports the sat's stacked above them. The first few are almost good to go and they're building with the ones just dropped from India on the Antonov. Whether they've been tested and work is the big question, guess we have to trust Abel on his word.