We gave up on piping after dealing with frustrations the few times I tried to play with it, but didn't want the hassle of bindings within our SVGs. @pturmel gave us the great idea to overlay a View Canvas on top of a SVG in a coordinate container, with both having the same dimensions. Highly recommend this route if anyone wants something where they can draw lines simply within a SVG, but use embedded views for components and interaction on top of them.