Honestly, it gets a little tiring hearing people tell me to fix a plugin which isn't broken. The plugin is working entirely as intended, aside from this error spam which happens occasionally and alone certainly wont cause your FPS to drop as you described. It certainly isn't spamming 1000's of times, I know what it causing the spam and it will be fixed soon when the next proper update comes out.
This plugin has already outgrown its original scope of being a simple plugin to call a Bradley which will be dropped to the location with basic AI making it patrol a small set path for players to take. I have incorporated many requested features and improvements since its first release and maintained it for Rust releases and bugs etc. The plugin is not broken, the AI was always intended to be basic. Just because you want more features and different AI doesn't mean its broken. The plugin was for sale at a price on its release for the plugin as it was when it was released and I have maintained its functionality and added more since.
I am hugely busy with work and family and had very important personal reasons to not focus on plugins which I will not go into. Other people might have walked away and abandoned plugins.
The next update is already started and changes are being made to include many of the same features as Heli Drops and I am working on the AI. This is a huge undertaking and will take time, so I make no promises for a release date.