Oh Emperor! Your new clothes do look wonderful!
Zero / minimal phase >distortion< perhaps? That'd be a Finite Impulse Response filter then...
Oh, but they don't want to be using such a negative word as "distortion" in marketing bumf.
Maybe try "maximum phase fidelity" instead of just avoiding the "D" word + sack their marketing dept + pay me a F.O. huge commission. (yeah, right).
Nothing to see here I'd venture, however a definite whiff of snake oil / BS. Oh, the smell of it.
Here's interesting though.
Found this from the annals of the Salzburg Konservatorium, circa 1800
Regard: the new UberKlingen.
Guarranteed to be nicer than your current StuckSheize in a manner that is not clearly defined or objectively measurable in any way.
Endorsed by Ludwig Van-Beethoven.
Only 5x the price of equivalent apparatus not carrying said endorsement.