The thing is AC21 applies to you as long as your I-485 is pending - the exact wording.
The law allows you to change the job, but the job must be same or similar. Also, the law states, that the burden of proof lies on you, USCIS doesn't have to prove anything. So, if in the future (at time of citizenship or upon investigation) should they allege that you broke the law - you have to prove that you didn't.
In this case EVL, W2s, and paychecks is enough to prove.