Openbuilds has 4-start (8mm lead) and 2-start (4mm lead) but not single-start (2mm lead) trapezoidal screw nut blocks. I’ve found http://usa.banggood.com/T8-2mm-Lead-2mm-Pitch-T-Thread-POM-Trapezoidal-Screw-Nut-Block-For-3D-Printer-p-1190076.html and https://usa.banggood.com/T8-2mm-Lead-2mm-Pitch-T-Thread-POM-Trapezoidal-Screw-Nut-Seat-For-3D-Printer-p-1190045.html but neither is solid. I tried cutting a tap from a piece of single-start lead screw, but it deformed the edges of the threads enough that there’s still a little play when I run it through a delrin test block. Not as much play as the normal brass nuts, but I can still feel it.
I found https://usa.banggood.com/TR8x2-HSS-6542-Trapezoidal-Metric-Tap-Ladder-Shaped-Screw-Machine-Screw-Tap-p-1052634.html which might work better than my hand-made taps, but does anyone have a source of solid 2mm lead screw blocks, to openbuilds specs so I can get out of this particular rabbit hole?