Just ran across this thread from last year. I have been flying indoor quads for about a year and making my own indoor quad kites. My focus has been on lightweighting the kites - so my current kite is an Orcon sail with ripstop edges and ripstop reinforcements where I’m guessing the biggest stresses will be. I like the lightweight character of Orcon but it can be fragile when I run into ceiling fans (which I do often) and I feel like it is a lot noisier than the all-ripstop sails I have made (all-ripstop is a but heavier but seems “stealthy” to fly).
I agree with comments in the thread that the low mass kites are not as good outside even on “calm” days because there are always occasional gusts that come up and make the low mass kites hard to control.
My current indoor quad weighs less than 100 g (3.5 oz) including fittings and spars and uses skyshark P90 tubes (three full-length in leading edge and each vertical is a full-length P90)
I’m still learning a lot about flying and building indoor quads - so this thread is really helpful