How do you switch out the default WebXR experience controller mesh?

Questions
15

webpack gives some good output, looks like scene helpers and scene loaders is quite big:

    webpack --mode production

    Hash: eea71a7286f30d7d04c6
    Version: webpack 4.41.5
    Time: 27950ms
    Built at: 06/27/2020 8:16:24 PM
                    Asset       Size  Chunks                    Chunk Names
          ../css/app.css   9.67 KiB       0  [emitted]         app
          ../favicon.ico   1.23 KiB          [emitted]
    ../images/phoenix.png   13.6 KiB          [emitted]
            ../robots.txt  202 bytes          [emitted]
                  app.js   1.62 MiB       0  [emitted]  [big]  app
      app.js.LICENSE.txt  808 bytes          [emitted]
    Entrypoint app [big] = ../css/app.css app.js
      [9] ./node_modules/@babylonjs/core/Engines/engine.js + 2 modules 86.6 KiB {0} [built]
          |    3 modules
    [10] ./node_modules/@babylonjs/core/Misc/tools.js + 1 modules 58.5 KiB {0} [built]
          |    2 modules
    [14] ./node_modules/@babylonjs/core/Meshes/mesh.js + 1 modules 177 KiB {0} [built]
          |    2 modules
    [21] ./node_modules/@babylonjs/core/scene.js + 5 modules 214 KiB {0} [built]
          |    6 modules
    [25] ./node_modules/@babylonjs/core/Engines/thinEngine.js + 5 modules 186 KiB {0} [built]
          |    6 modules
    [131] multi ./js/app.js 28 bytes {0} [built]
    [132] ./js/app.js 1.9 KiB {0} [built]
    [133] ./css/app.scss 39 bytes {0} [built]
    [134] ./js/socket.js 2.3 KiB {0} [built]
    [135] ../deps/phoenix/priv/static/phoenix.js 35.6 KiB {0} [built]
    [136] ../deps/phoenix_html/priv/static/phoenix_html.js 2.21 KiB {0} [built]
    [137] ./js/game.ts 5.75 KiB {0} [built]
    [138] ./node_modules/@babylonjs/core/Helpers/sceneHelpers.js + 93 modules 961 KiB {0} [built]
          |    94 modules
    [139] ./node_modules/@babylonjs/loaders/index.js + 53 modules 625 KiB {0} [built]
          |    54 modules
    [140] ./node_modules/@babylonjs/core/Maths/math.js + 1 modules 2.73 KiB {0} [built]
          |    2 modules
        + 128 hidden modules

    WARNING in asset size limit: The following asset(s) exceed the recommended size limit (244 KiB).
    This can impact web performance.
    Assets:
      app.js (1.62 MiB)