I'm afraid they are quite real, and it's the opposite, even if they are non-persistent they are still chemtrails, as far as i know they can be spraying even if you don't see the trails.
High bypass turbofan jet engines according aviation experts do not generate contrails.

Contrail science and metabunk are the same people.
Also i'll leave you a documentary about some of the things that are in those chemical trails.

https://steemit.com/chemtrails/@zedikaredirect/overcast-climate-engineering-documentary