Which game are you trying to fix? If you tell me, I can try to find specific installation tips or updated links for it.
K4sh's repository is frequently updated to include fixes for "unsupported" games or those with poor native ultrawide implementation: Senua's Saga: Hellblade II : Removing cinematic black bars and adjusting FOV. Elden Ring k4sh plugins
Would you like a (Bash skeleton + one demo plugin), a logo/wordmark idea , or a technical RFC for the plugin API? Which game are you trying to fix