I settled on the idea of a 'brush' or at least 'bristles' for my dust curtain. I couldn't find anything ready made, so I made my own. Works pretty good, and I'm confident when I upgrade to dual 2" vacuum lines, it'll be smokin'. I started by taking pliers and tearing out the tufts from a Harbor Freight workbench brush.
Try to carefully yet securely grab the entire 'tuft' of bristles with the pliers and rock the pliers to pull out the 'tuft'. Some will get messed-up. Keep going. It takes a hell-uv-a-lotta bristle tufts.
The Harbor Freight brush had a neat little staple like gizmo around the 'tuft' of bristles. This came in very handy when inserting the tufts into my motor mount.
I tried drill bits in the holes left in the brush to determine the proper hole size.
I flipped the motor mount upside down and put holes around the perimeter of the router in a highly un-precise fashion - just guesstimating the spacing.
Then I took a small nail set, and with a file, put a very slight "V" in the end. I would open the bristle bunch a bit, line the "V" of the nail punch over the small metal staple, align it with one of the holes I just drilled and smacked it with a hammer. Repeat until you start talking to yourself.
To the left is a close-up of the bristles in the motor mount. It actually worked quite well, and the bristles are held in quite firmly.
I didn't count 'em, but it took a lot of the little buggers to circle the router and dust port.