I’ve just noticed something strange.
In OpenFL Legacy TextFieldFormat is a static class with STRINGS as properties.
In Flash TextFieldFormat is an enum (probably), but still a type.
This means that if you want to pass a TextFieldFormat as argument to a function you have to put it as Dynamic to compile
function test(?align:Dynamic=null)
or as something like this
function test(?align:#if flash flash.display.TextFormatAlign #else String = null #end)
It does looks good, doesn’t it?
In OpenfFL NEXT it is an Enum, so the problem vanish.
It should be the same in legacy unless I haven’t understood anything, and in that case you have to forgive me 