yeah, coast to coast as you call it, can indeed increase skimming, although its depends on its entry construction. If its total length is used as an overflow, chances are due to surface tension & "Lip" condition it will still have distictive flow points. depending on total flow, it can also be ether quieter, or louder than classical form. Kudos to you anyways bud, especially cause its
DIY.
One question, on your pump pipes at the back - is the terminator caps at the top - are the sealed or breathable?