How to execute javascript code in parallel on Android without web workers?

Question

JavaScript

There is a javascript application that runs on iOS and Android through the browser component (in the case of Android, respectively, WebView).
The application contains complex computational logic that needs to be run in parallel. On iOS, the task was solved through web workers.
On Android, web workers are supported since version 4.4, which does not suit me. I wrote an emulation of web workers by creating additional WebViews. But it turned out that the javascript code in different WebView instances is not executed in parallel .
Is it possible to make multiple WebViews run on different threads?
Or alternatively, are there alternative ways to execute javascript in Android?
PS:
Found on stackoverflowconfirmation of my guess that in all WebViews, JS is executed in one thread.
Accordingly, the question is whether there are third-party JS engines for Android?

Answer 1

If there are no options to run the webView separately, it remains to implement the workers.