When hovering over an interactive element (e.g. a regular FlatButton), the text is drawn incorrectly as seen here (GIF):

Digging a bit more into it, it seems that when displaying the element as a flt-dom-canvas everything looks good but when its turned into a canvas element flt-canvas and checking the CanvasRenderingContext2D.direction it seems it is set to ltr even though the theme of the app is rtl. So bottom line, this optimization seems to be broken for RTL.

Testing with FLUTTER_WEB_USE_SKIA behaves correctly but it introduces many other different unrelated issues.

Flutter 1.23.0-18.1.pre • channel beta • https://github.com/flutter/flutter.git
Framework • revision 198df796aa (2 weeks ago) • 2020-10-15 12:04:33 -0700      
Engine • revision 1d12d82d9c
Tools • Dart 2.11.0 (build 2.11.0-213.1.beta)