Hey y'all thanks for the questions! Sounds like you both have some great project ideas and uses for the flanges which is awesome!
Carter is correct. When we did the redesign, we left the end clamp option off as it wasn't really needed by builders on its own. Now that we've got the flanges that utilize them it makes sense to add them back. I have updated the adjustable angle connector page to have the end clamp variant as an option again. @Carter37 @Casey45