I made some minor edits to make things easier to print and use.

Print one of everything except the brush plate, you will need two of them.

The TPU insert must be in TPU; I used one with 95 hardness from Overture. No supports needed.

I printed the Brush Screw and Brush Nut at 0.12mm layer height to prevent stringing across the threads, but the rest doesn't matter.

After printing, assemble in this order: Brush screw, Brush Plate, TPU insert, Brush Plate, Brush Nut. (Note: It is a little bit hard for the nut to “catch” the screw's threads. I also personally added a -0.05 x-y contour compensation on my own print for the Brush Nut to fit a little better but yours may vary.)

You can place the whole thing onto the Brush Stand, as it is removable for access. To use, you take it and insert the handle end of paint or makeup brushes from the bottom, and then set it back onto the Brush Stand.