when custom fields are added to checklist, the selection of the custom fields should auto select the checklist item and record the user/date time stamp the same as happens with a checklist item (default) when the left button is activated.
custom fields in this area usually would be a yes,no, n/a override of a simple button toggle provided by default.
additionally, having 2 custom fields (yes/no and notes) it would be great if you could mandate a note is entered for no, but not required for yes.