Fast-forwarding and seeking on a single key, with quality of life features like a slight slowdown when subtitles are shown.

Place evafast.lua in your mpv scripts folder.

Tap right arrow key to seek like default mpv, hold it down to fast-forward.
Playback speed will smoothly ramp up and wind back down.

Provides the evafast/toggle script-binding for speeding up independently of the hybrid key.