I would expect the baffle in the red sump to have cut corners and possibly cut outs along the bottom edge, so the oil can flow from side to side but not surge across in one massive splosh. It's what I would do anyway, and maybe will, if the RPM ones don't become available.
Since the alloy one is designed for a very low rear engined race car I assume it would be effective at preventing oil surge, and it looks like it will channel all the oil back to the pick up.