I have the Creality Silver metal extruder on an Ender 3 Pro. The hot-end is pretty much stock aside from a small part-fan duct, so I thought I would try the Stock_Direct_Extrusion version. It fits with very little fiddling.
The main issue is that the silver metal extruder is set up with a spring adjustment bolt that can clash with one of the mounting bolts. You have to insert the mounting bolt into the bracket first and then screw the adjustment bolt all the way in so you can tighten the mounting bolt.
To adjust the spring tension I have had to cut down an allen key so that it is short enough to get to bolt without fouling the bracket.
Performance - well that is disappointing. I was expecting big things on the stringing front, but this test shows a lot of stringing with zero retraction and even with 2 and 4mm there is still stringing. I was getting better results (very little at 4mm) with my standard setup.