The original ML_arms_01.stl with a 0.5 sized bump on it for cases with the mini base being held is half the thickness of a ModiLoop.    There's a tinkercad version of this as well if you want to re-mix your own.  Maybe you don't like the oval shape and want a straight up square nub or a cone with a sharper point so it doesn't mess up the painting of the base.

Edit: Added ML_arms_02.stl versions and added triangle and cone shaped bumps to experiment with different surface profiles.