Migrating Flex Application to Haxe and OpenFL using AS3HX

Hello Folks, I am new to OpenFL and Haxe, and i have some questions regarding migration from Flex to Haxe. We find it weird that despite of the good performance of OpenFL and the availability of AS conversion tools to Haxe like AS3HX, nobody seems to be able to use the Flex framework in OpenFL and Haxe.
What are the sticking points that prevent this migration, which enables Flex applications to be executed on HTML5 ?

I forget how much of Flex was available in ActionScript 3 form, or was precompiled and “off limits” as part of a core framework. I personally have wondered why the Apache Flex project hasn’t reached out about collaborating