HI I have printed off many funnels that were made for barista, express and other models but they DO NOT work in the Impress because the Impress has the automatic tamping system which has a different geometry. Eventually I decided to model my own that is as compact as possible . You can see in the video that the naked portafilter has plenty of clearance but the original portafilter hits the stainless steel plate . simply remove the plate if you are using the original portafilter while grinding. The fit is pretty snug and not sloppy

You can find the 3D printable file here. https://cults3d.com/en/3d-model/home/...

Printing details
Layer 0.2mm
Walls 20 (YES 20 you want it solid)
3 Top, 3 Bottom layers
NO INFILL
SUPPORT turned on and set it for anything over 85 degrees