Anycubic Kossel Plus Y-Merger

Experiment to build a working Y-merger for 1.75 mm filament - not specific for the Anycubic Kossel only ...
Tried already several iterations:
1) One part only (printed vertically) --> layer steps caused issues with filament move outside the tubes and material was less stable (also due to layer orientation) areas at mounting points of the fittings.
2) Split part (printed vertically) --> more "smoother" guide of filament (0.1 mm layer), but filament often stocks at Y-points
3) Actual state: sp