Is the Roadrunner compatible with the AF power supply?
It is not an Artisan Fidelity PS, it is an LDA (as specified) that AF happens to sell. I have no doubt you mean "does it work with the PS the same way it worked with Phoenix Engineering’s PS?" and the answer to that is "no". It will not automatically monitor and adjust the speed. But it does stabilize the speed such that after a brief warm up I rarely need to adjust it.
The primary benefit, as described by Artisan Fidelity, it NOT to offer speed control but to instead smooth the running of the very powerful but prone-to-noise induction motor.