Back in the day of Mafac cantilevers, and Modolos, for toe in,
we would just bend the post in relation to the shoe holder..

TRP also has an in-place angle adjustable brake shoe ,
though that VO one is cheaper. (+shipping)

Mafac cantilevers, with the Plain post , work well on touring forks
which have the bosses set up fairly closely spaced.

Shoe/post gets rotated downward, relative to the part,
as the posts get closer together.

Built a touring bike frame and fork in the 70's
The first brake adjustment
was where I put the brake bosses on the frame.