I've come to realize that the JOIN tool is case-sensitive by design but it would be helpful if you could turn that behavior on/off (via checkbox?) within the JOIN tool. For those of us that work predominantly in database environments that are not case-sensitive, this default behavior has caused me problems many times. Having to force the case to either upper or lower upstream of the JOIN on both flows in order to ensure a successful join is an extra step that would not be necessary if you could disable case-sensitive with a checkbox.