How to not enforce 'contains' for matching the results and allowed values

I am using PHP code to populate the allowed values list. The php code uses an external enterprise api to match on user names.
The api returns all the matching names. However before showing the names to the user, the autocomplete module calls -
autocomplete_widgets_json() -> _autocomplete_widgets_get_options() -> _autocomplete_widgets_get_options_allowvals()

The _autocomplete_widgets_get_options_allowvals() function uses the autocomplete match criteria and only has options of 'contains', 'equals' and 'starts with'.

This is truncating some of my results. I am planning to write a patch to bypass this check by providing an 'ignore' option which will allow us to show all values.

Please advise.

My use case: I want to search for James Cameron. When I type jamesc I find the match since James Cameron contains jamesc.
However when I search on 'cameronj', my service returns James Cameron but this function prevents it from being listed since James Cameron does not contain 'cameronj'.