'How to capture widget that is not in tree using compute function?

I use screenshot to capture widget that is not in tree and works. But if I try to capture complex and high resolution widget it freezes the UI for a while. Then I use isolated thread/compute function.

This is simple code you can try to reproduce.

Future<Uint8List>captureWidget(String value) async {
    ScreenshotController screenshotController = ScreenshotController();
    return await screenshotController.captureFromWidget(Text(value));
}

then call

Uint8List capturedWidget = await compute(captureWidget,"Test");

I got this error

[ERROR:flutter/lib/ui/ui_dart_state.cc(209)] Unhandled Exception: Exception: 'dart:ui/window.dart': Failed assertion: line 298 pos 12: '<optimized out>': is not true.

Is possible to capture widget that is not in tree using isolate thread?

flutter flutter-layout

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'How to capture widget that is not in tree using compute function?

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