Can plugins PERMANENTLY change ur code?

Can plugins PERMANENTLY change your code?
In this case, I’m trying to figure out if it’s safe to test WP Minify, which simplifies your code, to save bandwidth. (this plugin here: https://www.ads-software.com/extend/plugins/wp-minify/)

Also, does anyone know if WP Minify will interfere with DB Cache Reloaded or Hyper Cache? I’m thinking no, but I’m not sure.