I used PLA+ to make the inserts with a curved interface for feeding the filament into the Filament Guide Addon (Originally for the MK4 -  but fits the MK3S+ perfectly)

Used eSUN PLA+ 

0.15mm Quality resolution, 

Nozzle 205,  Bed 65 and used 

Organic Supports to optimise the inlet curvature for the filament.

They seem to work pretty well, and can be replaced easily when they become worn.