2.5mm wire holes support wire up to 1.5mm in diameter (maybe even 2mm depending on your printer's tolerances). Any bigger and I find there's too much friction when pulling the wire.
Occupies a 4x2 Gridfinity footprint.
Print
I used Sunlu PLA+, with mouse ears on the corners to reduce warping.
Model
Fusion 360 model file is included in case you need to tweak.