I'm certainly no expert but I've done a few that had me crapping in my pants so....
Use pins. They take the expansion out of the flake, try starting with a pin.
Use as much clean gear as possible. If you place two pins in a row, placing the second will loosen the first until it pops. If you must place two pins in the row, set the second then clip into it tight with a daisy. Keep pounding. When the first pops the second should hold your weight. Scary! but it works.
Use hooks. Sky hooks obviously avoid the flake. Cam hooks fit nice in pin scars and won't pop (at least not as easily)when placing pins above.
There is lots of Expando flakes in Squish. The only expando flakes I've climbed at Index were on Golden Arch. Just a few moves but mixed in with sketchy hooking, fixed heads and such it certainly gets the blood flowing!