I've created a minimal repro of a swf that looks different in openfl than flashplayer. you can download the fla/swf zip here
the image below shows the difference.


The left is how it should look, the right is how it looks via openfl. ignore the yellow that is unrelated. I made this by drawing the number 4 with the paint brush tool, i copied the result to a new frame and applied Modify->Shape->straighten (might have been advanced straighten) and the straightened version seems to be showing incorrectly
I've created a minimal repro of a swf that looks different in openfl than flashplayer. you can download the fla/swf zip here


the image below shows the difference.
The left is how it should look, the right is how it looks via openfl. ignore the yellow that is unrelated. I made this by drawing the number 4 with the paint brush tool, i copied the result to a new frame and applied Modify->Shape->straighten (might have been advanced straighten) and the straightened version seems to be showing incorrectly