Event Listening Using MapboxStyleImageryProvider

I would like to listen to when MapboxStyleImageryProvider has finished loading the base layer tiles from its resource request. In my app the mapbox images are the very last resource to load on the viewer and I would like to delay a process until everything has loaded.

My initial take was to add an eventListener to ImageryLayer.readyEvent however, this emits as soon as my baseLayer is initialized way before the images from Mapbox get loaded. I also tried adding a callback to when the ImageryProvider.readyPromise resolves but this exhibits the same issue of emitting true before mapbox api url is even called.

My guess is that the HTTP2 fix mentioned here: Slowness in loading base layer tiles from Cesium.MapboxStyleImageryProvider will solve my loading issue. Unfortunately, I’m restricted to using v1.106.0 since that is the latest version published for the paid version of cesium (afaik).

Is there a simple work around for this? I would like to avoid having to write a custom proxy for the mapbox api calls to intercept and respond to any loading events