Actually, I was mentioning in #2, that if one wishes to go back to H1/H4 after a brief period of employment using EAD. Then the only way is to leave the country and re-enter on H-stamp.
As you mentioned, If the person intended to continue to work on EAD then he will have to use A.P not worrying about his H/F visa stamp. But, remember he will be treated as "immigrant" in the eyes of CIS.
In future, he may be subjected to H1-Cap numbers in order to file new H1B petition. If his immigrant petition is denied for whatever the reason in future, it becomes illegal stay depending on how many days/years he stayed as on immigrant. So, there are too many risks involved by taking this approach. Thats why the safest best would be, to continue on H/F status as long as 485 is pending. As H/F recognizes dual intent nature.