if you have a need to consider `true` as being equal to `"true"` then you would pass a function as the `query` and put all your custom logic in that.  SimpleQueryEngine has a great deal of flexibility built into it already so that users can provide custom filtering and sorting logic without needing to include every possible case.  i'm not seeing any changes to this file that couldn't be achieved with extension points that are already available in SimpleQueryEngine
* you can provide the query as a function with your custom filtering logic
* you can assign a function to `options.sort` that will allow you to customize your sorting