Eb2 to Eb3 downgrade previous employer

Hello Friends,

My previous employer with whom I had a Eb2 approved I140 was willing to take me back and has filed my downgrade Eb3 and AOS end of December. Frankly I am not a 100% thrilled to go back to my previous employer but completely understand the privileged position I am in. However my biggest fear is joining them on H1 and then there are issues with my downgrade and AOS and now I have taken a step backwards.

What are some things that I can keep in mind to make sure that my AOS is not denied and I at least get a valid EAD.

Also now that 3 months have passed since new years bulletin, has anyone had any success in applying for premium processing for downgrade EB3?

cc @Anil_Gupta