once you use EAD, you will be AOS, like radiology says

Then when you obtain an H4 from US consulate, and come back, then you reverse to H4.
Again you use EAD, you will lose H4.
So, what's the benefit of using H4 visa instead of using AP to return?

也就是说 H4不影响工卡身份,但反过来会影响,
对吗?
If you don't EAD, you will keep H4, though you are holding an EAD.