Roller-brearing z-screw experiment (Dollo3D)

This is a fully 3D printable z-screw roller-bearing thingamajig I came up after couple of years tinkering with Dollo3D and trying to get a fully 3D printed Z-axis done. It is quite possible that there's a wee bit of over-engineering in play here, or simply madness, but the idea actually works and I've had this running on my Dollo3D.2 printer for over a year now and after more than 500h of print time, it's still going on strong. I had a looksee inside the contraption few months ago and there isn't even noticeable increase in play between the parts which I find quite supprising. Also the accuracy of the z-axis is supprisingly good. The thing is quite loud, though...

So what and why? In the beginning I was going for a simple 3dprinted screw-nut combo, but I started thinking that with plastic parts the screw would wear out unevenly (because we hardly ever use full z-height) so I started thinking about somekind of bearing where the wear doesn't happen on the screw. So after few scrapped