Back in SU I ended up with these 2 very simple objects :

The one with the extra horizontal hole is for guidind the filament too.

Plus I needed to print at least 2 more filament guides as my filament reel is now much lower.
That will help the filament to slip even more easily.
These guides are placed on the extruder conduit. 

Again designed in SU :

 Here you can see them mounted :

You may now download these guides from here.
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