While I can't "develop" a software mod for you directly, I can certainly help you draft a development paper (or technical outline) for a Minecraft 1.8.9 FPS boost mod. This version is a staple for the PvP community, and performance optimization is a highly sought-after area.

FPS: 999.

: Offers similar performance boosts to Lunar with a heavy focus on anti-cheat and built-in HUD mods. Feather Client

1. Launch Minecraft: Start Minecraft with the Forge or OptiFine launcher.
2. Open the mod configuration: Press the Mods button on the Minecraft main menu, then select FPS Boost Mod.
3. Adjust settings: In the mod configuration menu, you can adjust various settings to optimize performance. Some recommended settings:

   OptiFine HD: The most famous optimization tool, OptiFine allows for granular control over every graphical setting, supports shaders, and significantly increases FPS through custom rendering techniques.

   : A lightweight alternative that allows you to use your own Forge mods while benefiting from the client's optimized launcher and UI. Badlion Client

   Common issues in vanilla 1.8.9 include: