Even on the latest version of Autocomplete Plus, using this extension causes editing PHP files to be almost impossible due to the lag it creates. There's an open issue about PHP performance in general, but it seems like the latest version has helped with that. I'm not sure if there's something that can be done within Autocomplete to help with this, but it seemed worth opening an issue here about it as well.
Even on the latest version of Autocomplete Plus, using this extension causes editing PHP files to be almost impossible due to the lag it creates. There's an open issue about PHP performance in general, but it seems like the latest version has helped with that. I'm not sure if there's something that can be done within Autocomplete to help with this, but it seemed worth opening an issue here about it as well.