The goal - allow text to be entered into the SfComboBox text box that does not match any entries in the ItemsSource list. Have the
SfComboBox text box text property two-way bindable to a data source.
This basically becomes the merge of a .NET MAUI Entry box and the SfComboBox.
This is traditional behavior for a ComboBox. As is, SfComboBox is functioning like a ListBox.
Currently the only two-way bindable path to a return value is SelectedItem or SelectedIndex. Also the SfComboBox has only two TextSearchModes - ComboBoxTextSearchMode.Contains and ComboBoxTextSearchMode.StartsWith.
What I would propose is the addition of a two-way bindable property - SfComboBox.TextBoxText, and an additional SfComboBox.TextSearchMode of ComboBoxTextSearchMode.None. The latter preventing the user entered text box text from being overwritten unless a manual selection is made from the dropdown list.
I recognize that this makes entry completion events a bit more nuanced but the Unfocused exists and an IsEntryCompleteButtonVisible could automatically appear when TextSearchMode = None.