It should be possible to start the map inside a particular indoor map on a particular floor

[Tim Jenks]

The orchestration to enter an indoor map, to a particular floor, should be encapsulated and exposed as a configuration option to L.Wrld.map:

var map = L.Wrld.map("map", "your_api_key_here", {
        center: [37.7858, -122.401],
        indoorMapId: "",
        indoorMapFloorId: N
      });