We've modified the brackets that have been part of our Center Bar and Leveler Kit for several years with an elongated slot so that they can be installed on the underside of our Stabilizer Bars.  These Stabilizer Bar Levelers, sold in pairs, allow vertically adjustable support for the stainless steel rods of the Circle or Ellipse Jigs when cutting large radii (more than 24").

See how Rich utilized them for one of his projects.