Let's analyze the code you provided:

This code checks if the user agent contains 'yhdandroid', indicating it's running in an Android WebView. Then it attempts to handle the back functionality.

The current implementation has a few potential issues:

1. It doesn't account for multiple forward navigations. If a user navigates forward multiple times, window.history.go(-1) will only go back one step, which might not be the desired behavior.
2. The check window.history.length > 1 might not always accurately represent whether there's a previous page to go back to, especially after multiple navigations.
3. There's no handling for cases where window.history.go(-1) might fail (e.g., if there's no previous page in the WebView's history).

To improve this code and ensure it works correctly with multiple navigations, we can make the following modifications:

This improved version addresses the issues in the following ways:

1. It introduces a position state to track the navigation depth within the WebView. This allows for more accurate back navigation.
2. The goBack function checks the current position in the history. If we're not at the start of the WebView history, it uses window.history.go(-1). Otherwise, it falls back to the app's native back function (window.yhd.back).
3. It overrides the default popstate event to handle cases where the WebView is at the start of its history, ensuring the app's native back function is called.
4. It adds listeners for pushstate and replacestate events to update the position state whenever navigation occurs within the WebView.

This solution should handle multiple navigations more reliably, ensuring that the back functionality works as expected in various scenarios. It maintains the WebView's history when possible and falls back to the app's native back function when necessary.

To implement this in your app:

1. Replace the original code with this new implementation.
2. Make sure to call the goBack function when your back button is pressed.
3. Ensure that window.yhd.back is properly implemented in your Android app to handle native back functionality.

This solution should provide a more robust handling of back navigation in your Android WebView, accounting for multiple navigations and edge cases.