After reading through several threads of frustrated owners who can't find anything beside PIAA, OEM, and Trico refills for the driver's side, I decided to seek out a solution for replacing the wiper arm.
When ordering wiper blades, I realized that the 2010 Legacy has the same size blade (26") and a similar arm size. So yesterday, I borrowed the arm from my mother's 2010 and swapped it onto the Tribeca. It works! It's not 100% the same coverage, but it's still effective and there's no interference between blades.
Some photos:

As you can see, it sits pretty well over the heated wiper area, although I never found the heating element that effective when it's really cold.
Comparison of beam coverage. The Legacy goes a little bit lower on the bottom and top. Being 6'2" and sitting tall inside the 'Beca, I would say that the coverage on the top is adequate, it's much less extreme than it looks in the photo (not the best quality):


The Legacy part # is: 86532AJ020 and it's ~$35-40 depending on where you go.
The cap specific to the Legacy arm is 86538FG000 and it's about $3 or under.
When ordering wiper blades, I realized that the 2010 Legacy has the same size blade (26") and a similar arm size. So yesterday, I borrowed the arm from my mother's 2010 and swapped it onto the Tribeca. It works! It's not 100% the same coverage, but it's still effective and there's no interference between blades.
Some photos:

As you can see, it sits pretty well over the heated wiper area, although I never found the heating element that effective when it's really cold.
Comparison of beam coverage. The Legacy goes a little bit lower on the bottom and top. Being 6'2" and sitting tall inside the 'Beca, I would say that the coverage on the top is adequate, it's much less extreme than it looks in the photo (not the best quality):


The Legacy part # is: 86532AJ020 and it's ~$35-40 depending on where you go.
The cap specific to the Legacy arm is 86538FG000 and it's about $3 or under.