Love the original version of the adjustable table cloth clamp by @fl_mike. One outstanding issue is the “triangle” in the slide that needs supports. I added a sacrificial support, 0.2mm thick (one layer) as a bridge under the triangle that should be much easier to remove than slicer-generated supports.

All other print settings remain the same. If the clip is oriented lengthways in the Y-axis, I did not need any brim. 

To remove the sacrificial support, I found that a narrow flat blade jewelers' screwdriver and a utility knife did a good job. In the picture, you can see a little bit of the support after cleanup on the right side, but it doesn't affect the sliding action at all.