my crusts at 20% starter were fantastic hand mixed after 8 days cold rise, and I actually let this dough warm rise for about 2 hours with 3 or more half hour s/folds before fridge. I haven't checked the temp on my fridge.
my crusts at 12% starter were even more fantastic after 4 days cold rise, but mixed in the KitchenAid and then straight to the fridge. (different oven temps)
I cannot see my dough falling apart using 40% starter.... although I imagine it would be very slack. Guess the only way to tell is to try it. lol. Of course my logic is faulty due to my basing it on the fact that I used a large amount of starter to make sourdough bread
a few weeks back, and I did not bother to attempt creating a boule with it cuz I knew it would stick to everything, but the bread was fantastic baked in a loaf pan. It had an ethereal quality both in taste and texture to it that I cannot adequately describe, and I kept thinking about taking that exact recipe and trying to make pizza with the dough. SO I guess I better check the percentage of starter in that dough recipe before I start making assumptions that it was anywhere close to 40% starter.