I really like the idea of one vessel brewing, and the reverse recirculation thru the malt pipe during the mash. Maybe you could devise a method of reversing that flow at the end of the mash to clarify the wort thru a settled grain bed, even if it is after lifing the malt pipe after the mash. This would allow for clarification of the wort.
Are you planning on a US version of the 50L system?