The difference is that the new tensionner of the Birdy 3 is not rigid as this one (and several others), its a spring loaded deformable parallelogram. Due to this concept, it works without any extension on the derailleur cage.

This new tensionner is not specific to Pacific Cycles, its also a R&M development, the Birdy 3 touring (10s derailleur) and Birdy 3 Rohloff of R&M are equipped with this tensionner, its only the Birdy 3 City that doesn't have it.

This is the tensionner sold by a Dutch R&M reseller (Kemper Fietsen).
And this is the damper of the front fork which seems cracked on your Birdy.

Unfortunately, they ship only to The Netherlands and Belgium