Thank you so much for the kind words and for standing up against the negativity! I'm really glad you're enjoying the plugin and finding it useful for your server. <3
And yes, you'll be happy to hear that LagFixer is already open-source!
You can find the source code here:
https://github.com/lajczik/lagfixer
Contributions are more than welcome! Feel free to submit pull requests, report issues or suggest improvements. I'd love to see what the community can help build.