What is my age protection status as an EB-5 derivative who is waiting for I-485 approval?

You have an involved situation. You need a consultation appointment with an immigration attorney.

As long as you qualified for CSPA before filing your I-485 I understand under the new rules based on a recent court case you will be considered still covered while I-485 is pending but actual guidelines from that case have not come out yet. Before this ruling, you had to qualify for CSPA at the time of adjudication under the Final Action Date chart.

Without your date of birth, the date of petition filing and approval, the date the DS-260 was filed, and the date the I-485 was filed, no one can calculate the CSPA age. Work cards take a few months, travel cards take longer. Good you are transferring H-1B status especially if you aged out.

You state that you already applied for an I-485 but paid the NVC fees (consular process) before aging out. Did you apply for the I-485 before turning 21? As for the Employment Authorization, you should receive it from 6-8 months after applying for the change of status.