Investigating Persistent `Promise.all` Pending State: Are Microtask Queue Dynamics Impacting Resolution?

Having addressed fundamental pending promise issues, I'm now encountering a more intricate problem with `Promise.all`. Despite all individual promises within a `Promise.all` aggregation appearing to resolve successfully, with their respective `then` or `catch` callbacks executing as confirmed by extensive logging and instrumentation, the `Promise.all` itself consistently remains in a pending state indefinitely. This behavior is perplexing because the internal state of each promise contributing to the aggregation indicates completion, yet the aggregate promise never transitions from its pending status. I suspect this isn't a basic unhandled rejection or a simple case of an individual promise failing to resolve at a granular level. Instead, I'm leaning towards a deeper interaction with the JavaScript event loop, specifically how the `Microtask Queue` processes these resolutions, or potential contention or saturation within it. I'm considering scenarios where a very high volume of microtasks, perhaps from other asynchronous operations, or an unexpected long-running microtask, might prevent the final `Promise.all` settlement from being scheduled or executed in a timely manner. How can one systematically diagnose if `Promise.all`'s final resolution is being delayed or blocked by an overloaded `Microtask Queue`, or by an unexpected ordering of promise handler executions that prevents the aggregate promise from settling effectively?