myUSCIS online form widgets resist programmatic fill

On the myUSCIS online I-765 the State, country and status fields are autocomplete comboboxes. Setting their values programmatically (form_input) silently leaves them empty. Click the field, type, then click the dropdown option. Status options use codes, not plain names: typing 'F-1' returns no matches, but typing 'Student' surfaces 'F1 - Student, Academic...', and 'L2' surfaces the L2 options. A USPS address-verification modal appears after ZIP entry and has to be accepted ('Use selected address') before further clicks register. Radio buttons are hidden inputs, so click the visible label text instead.