Hi V, thanks for the thoughtful response.
I'm not really an expert on Taoism, apart from what I learned from the Tao of Pooh and elsewhere on the internet, but I'll try my best to give you an answer.
Perhaps, I'll draw upon the metaphor of Aikido, a Japanese martial art. While it has a different origin from Taoism, the philosophy of Aikido is highly similar to Wu Wei.
Aikido differs from other martial arts because of its emphasis on flow and harmony. It doesn't rely on violence or sheer force. Instead, Aikido focuses on aligning yourself with the enemy and using their strength against them.
What I want to say from this is, even in a martial art setting where two completely antagonistic sides fight head-on, there's still a way to prevail without using force: By flowing with the enemy.
Taking the path of least resistance and using minimal effort. Just like Wu Wei, right?
I understand that in the context of social justice, the situation might be more complex because we're not fighting against a tangible enemy (for example, instead of fighting racists, we're fighting against the idea of racism itself).
However, I believe there's still a possibility to practice Wu Wei while fighting for social justice. I don't think I'm qualified to prescribe a specific method, but that's the general idea.
That's what I got for now, I hope you find this helpful. Cheers!