We've fixed a couple of noise problems at our office (exhaust fan in break room, couple of very short return-air paths) with flex duct (stuff is very good for not passing noise), but never seen an entire system done with it!!
Looks like a bunch of snakes during mating season! SNAKES in the ATTIC! "I am getting tired of these M@(*%!----", well you get the idea. On pic 2 did they only have one size of duct so made a double decker wrapped seperately?
I saw one Saturday I should have taken pics of. A 2.5 ton unit with a 12in compressed flex return and a 2ft long box on the supply with 8 4in flex ducts coming out. All loosely run and highly compressed, a true "ductopus". Evaporator had at least 6 distinctive leaks in it and the customer just wanted it topped off, what a joke.
"If you've eliminated all other possibilities whatever remains must be the truth."