I've been a big fan of equivalence tests in JMP. For a one-sample scenario in the Distribution platform I like the output because it has a nice graphical representation of the equivalence bounds overlaid with the confidence intervals on the mean. You also get a deliberate interpretation statement at the bottom.
My proposal would be to create similar output in Fit Y by X as to what you see in the Distribution platform. For the example above, the equivalence bounds of [-6, +6] can be easily shown with a red confidence interval based on the actual output (centered around 3.02).