The inner tent has elastic loops that are sewn into the top seams, the elastic loops go through bullet shaped toggles (cant remember the exact name for them).
The flysheet has grosgrain loops sewed into the flat felled seams, 1/2" stuff is fine, there is not a lot of stress on them. The grosgrain goes through 15mm 'O' rings. To attach the inner tent, feed the toggles through the O rings.
I changed to clips for the top half of the poles as the sleeves were catching the wind and appeared to be putting a strain on the poles up top. My knowledge of aerodynamics is extremely limited, but I suspect the wind hits the side of the tent then accelerates upwards. Either that, or the wind is just stronger at that height, or just catches on the lip formed by the sleeve.
The clips definitely work better, and the fabric is still plenty taut. Whether this would work the full length, I don't know. I prefer to have the poles in continuous sleeves built into the flysheet wherever possible, preferably flat pole sleeves, like in the single pole tent.
Bear in mind that if it is all clips, it is going to take longer to set up. Not what you want with cold hands and dodgy mountain weather. I can feed the poles through the clips at the top, rather than clip them on, as the poles are already pretty much held in place from the sleeves lower down. Clips are also heavier than sleeves.