Just a suggestion for improving the sqlite performance based on what I’ve done on my installation:
add “$this->pdo->exec(‘pragma synchronous = off;’);”
after the " $this->pdo = new PDO(‘sqlite:’.$settings[‘filename’], null, null, $options);"
It dramactically improves the responsiveness when sqlite gets above 3000 tasks.
That being said, make sure you are running on a stable system and backup regularly since sudden OS crashes or power outages can result in corruption - Pragma statements supported by SQLite