This is one of my two designs (Here's the other one) for a Quickmill-Portafilter stand and tamperstation.
As we all know the recommended pressure for tamping is 14kg, so I had some doubts regarding stability, but with 25% infill this thing is solid as a rock.
In the back of the station is a cutout for a rubber tamper-mat , I got mine from Amazon, its called "scarlett espresso Puck" - this can be taken out for cleaning.
Affiliate link to the rubber mat
Polymaker Polymax PLA
Infill 25% probably too much.
I had supports for >50° for the overhangs which worked out nice, but regarding your filament and printer this isn't necessary.