My extruder tends to jam when not guiding the filament in the middle, so I designed a filament feeder. It is secured with a tie-wrap through the not used (by me) bolt slot for the second idler spring.
Added version 2, because my hobbed bolt still pulls the filament to the side. This new version has an actual guidance cylinder instead of a hole only.
Print, secure with a tie wrap, and feed the filament through.