The premiss of all chemtrail arguments and delivery concepts are impossible. End of story. There is literally nothing more to explain.
As for whether contrails have changed, take a look at WWII dog fight footage and photos. If a piston engine can condense moisture into a contrail that lasts for minutes to hours then a high bypass jet sure as hell can condense enough to do the same.
Rather than looking at pseudo science why don't you first look at the real science and hard and fast rules of aviation, meteorology and physics then see if you can find any possible way for there to be any kind of truth behind it.