Rotated the bracket for the Q2 Box 4 to 1 Splitter/Manifold to horizontal so that the 4 PTFE tubes entering the manifold have a lesser radius curve and a longer ‘straight path’ before reaching the manifold.  Others found this orientation resolved filament loading errors.  Q2 support just showed me/suggested the same orientation today.  Note: You will need a longer PTFE output tube from the Splitter/Manifold to keep the curve radius of that piece acceptable.  I used another model quick disconnect to joint the original PTFE and an extra piece to accomplish this.  Fair warning - my filament occasionally catches at the junction - I will upgrade my extra PTFE tube (2.5x4 mm like on a Prusa) to 3 mm ID that QIDI says they're using on the Box to see if that helps, or find a better solution to join them.  You could just replace the whole piece but I like being able to run filament from an external spool into the system (like TPU you shouldn't run in the Box) so I will work to improve that junction.