The best way to think of jit.world is as a drop-in replacement for the typical qmetro/t b b erase/jit.gl.render/jit.window combination. It adds a few more bonus features like being able to output a matrix or texture render, but for most patches, it's pretty simple. That said, if you have patches that work great as is, there's probably not much incentive to change it unless you want some of the jit.world convenience features.