Hello Lana,
here my homework for lesson 6.4.
I've used 2x1.6 while for long tails I've used 2x1.8.
Probably is better 2x1.8 on circular appliques, because 2x1.6 makes difficult to curve and tension the biflex with hands.
Anyway, I undone the work several times because it was difficult to stay close to the biflex/mesh junction.