> The whole point was that he went far enough away (sailing, Australia) to not only speak with the anger of the injustice (what happened to him), but to target the structural aspects (how enslavers are made)

Going far away won't help with targeting enslavers. If you're enslaved in Africa, the enslavers are in Africa.

Dunno. A lot of the slavery in Africa went partly as the result of British abolitionists.