yes

It is the "use" of the EAD or Advance Parole that takes away your H-1B status. How do I know I used the EAD? You use the EAD in one of two contexts. One is that you use EAD with the same employer (H-1B) and your employer amends the form I-9 to change the employment authorization basis from H-1B to EAD for your payroll record, which you sign. The other situation is you use the EAD to work for a second or third job outside of the H-1B employment. In that case, even if you did not change the record of I-9 with your H-B employer, you lose your H-1B status. Once you lose your H-1B status, unless you leave and return with a new visa or a new H-1B I-94, you cannot reinstate the H-1B status. Again possession of the EAD and Advance Parole may be very important as a back-up when the situation changes, but until you use it, you will continue the H-1B nonimmigrant status. Drawback of working on EAD rather than H-1B is that you fall completely out of status when I-485 is denied, but such disadvantage is sometimes offset by disadvantages that comes with the continuing H-1B employment with the violation of Labor Condition Application or H-1B regulation, for instance, wages or locations, etc. When you work on H-1B pending I-485 application, you will have to comply with the H-1B regulation and LCA terms. If you violate such terms and regulations, you will not be eligible for I-485 application. Accordingly, when you face a situation wherein you may have to violate the H-1B status for whatever reasons, you may be better off working on EAD. Once you violated the H-1B status and LCA conditions and there is a reason for you to believe from the RFE that the USCIS is pusuing such violation, you may have an option of refiling I-485 to take advantage of so-called 245(k) benefit if your violation was less than 180 days. Section 245(k) allows you to file I-485 inasmuch as overstay or unauthorized employment which had been committed "before filing of I-485" was less than 180 days. Under the current USCIS policy, the same violation after filing of I-485 is considered "outside of the parameter" of 245(k) provision. Accordingly, in order to take advantage of 245(k), depending on the urgency, people sometimes refile I-485 application.