Request-Transformer with X-Forwarded-* unable to work

I found out a logic from “kong/runloop/handler.lua”, and I let trusted_id pass all(,::/0), then using Postman send a request with X-Forwarded-* header modification, which can work, but this plugin can’t, I doubt Request-Transformer can’t work/modify for NGX.VAR, It that a bug or have other concerns?