No personal experience, looking at the pics at
https://www.cjponyparts.com/flowmas...-stainless-steel-fiesta-st-2014-2019/p/CBF71/ it looks kinda like a flowmaster 50 series muffler with a small resonator. The 50 series is a delta flow so I doubt it's doing any active cancellation in the fist-typical 3200 rpm range, an the length of the front resonator isn't long enough to touch that range either, so chances are it's probably going to drone a bit. The short front resonator is probably there to make it less raspy - there are tons of sound clips and it sounds pretty decent, if perhaps a little hollow.
As is always the recommendation, if hate drone, go Thermal (their quarter wave resonator is spot-on for cancelling FiST drone). If you dislike drone, go CP-E (their helmholtz chamber covers a slightly broader range, but is a little undersized to completely soak up 106.67hz frequencies). If you don't mind drone, get anything but MBRP (they'll all vary in severity, but none of the other options actively target the 106.67 range of frequencies). If you love drone and hate having the ability to hear, get an MBRP. If you hate money and want to throw it all away, build a few custom systems, do acoustic research, and buy/modify an MBRP to prove it can be tamed