I have two portafilters and wanted to mount them with one rack and with less material than the original. I removed excess material and put 2 of them in line and I think 2 screws are enough for a secure mount
You can use upto 4,5mm screws - I've used 4mm ones
The author remixed this model. Imported from Thingiverse.
Mount for two portafilter instead of the three