I hope that you get Chaz to stop this. They do it for several reasons:

(1) The taste. Plastic is made from oil which is a vegetable product to begin with. **

(2) Cats chew on long grass and thin twigs outside. Some cats love chewing (on almost anything). My boy cat love playing with string. Not for chasing the string but chewing on it.

(3) Boredom.

For (1) you can use the covers and sprays. Some people use hot sause. Numbers (2) and (3) are behavioral. The cord covers will help here.

The tubing is plastic and may taste the same as the cords. They will delay the cat getting to the actual cord.

** I know my science. Oil is actually decayed vegetable matter that has been in the ground for lots of years.