Pretty sure bento had an "autocomplete" option, when you are working on specifying the fields, that you could turn off and on.
However, everyone's memory is becoming fuzzy fast on Bento, considering it was discontinued over 2 years ago and support ended soon after.
Thank you for your post.
In Bento, on the left side of the window are the Libraries. Below the Libraries lists the fields for the currently selected Library. If the fields are not showing, then click the triangle icon in the bottom left corner to display the fields. In the list of fields, find the field that is performing the auto-completion, and double-click that field. A window will appear titled "Edit the Text Field." At the bottom of that window is the section "Set options" that displays a checkbox "Automatically complete text while typing". Uncheck that box and click OK. The auto-completion for that field will no longer occur.