conflict between flutter tree shaking and non-constant instance of IconData

Question

In a mobile application I'm trying to construct material icons based on icon data point obtained from server, here's a minimal version of the conflicting code

class CustomIconFactory {
  static CustomIconFactory createIcon(IconParameters parameters) {
    Widget widget = Icon(
      IconData(
        parameters.iconId,
        fontFamily: "MaterialIcons"
      ),
      color: Color(parameters.colorId),
    );
    // more logic here
    return CustomIcon(
      baseIcon,
      // more optional parameters here
    );
  }
}

when executing flutter build apk, I get the following error

This application cannot tree shake icons fonts. It has non-constant instances of IconData at the following locations:
  - file:///C:/Users/Admin/Desktop/mobile_application/ips-mobile-application/lib/power_animation/data_structures/power_flow_animation_parameters.dart:44:7
Target aot_android_asset_bundle failed: Exception: Avoid non-constant invocations of IconData or try to build again with --no-tree-shake-icons.

I don't know why, although other parts of the code use similar approach with no problems (inside a static method, and having the icon code point extracted from a parameter class).

thanks in advance