I would like to repost this issue and ask, if there is any chance that the AutoComplete method is also called when the last character is deleted (e.g. with backspace or delete key). I think that this would be a very simple change and would help to get rid of a lot of workarounds which in the end are all not that good as just calling AutoComplete with an empty string. In addition the behavior would be compatible to 3.x versions.
Is it enough to post this issue in this forum, or should I open an issue for that?