frida issue: early instrumentation in gadget (interaction type == listen)

configuration:

{
  "interaction": {
    "type": "listen",
    "address": "127.0.0.1",
    "port": 27042,
    "on_load": "wait"
  }
}

script:

rpc.exports = {
  init:  (stage, parameters) => {
    return new Promise((resolve) => setTimeout(resolve, 20000));
  },
  dispose: () => {
    console.log('[dispose]');
  },
};

run it:

frida -U Gadget -l test_compiled.js --runtime v8

I see Attaching ... for 20 seconds but the application starts immediately and I see all its activity during this time, but in documentation:

Gadget calls your init() method and waits for it to return before letting the program execute its entrypoint. This means you can return a Promise if you need to do something asynchronous, e.g. Socket.connect(), and guarantees that you won’t miss any early calls.

the expected behavior (correct) is observed with this configuration

{
  "interaction": {
    "type": "script",
    "path": "/data/local/tmp/test_compiled.js"
  }
}