What would happen if your ncoer goes past the 90 day limit and it is still with supplementary reviewer?

SSG(P) (Join to see) at the 90 day mark, the BC and CSM get involved.

Likely if it is getting close, they are aware and probably already spoken with your 1SG and CDR.

For you, not much will happen. If you want to be proactive, IAW the regulation, it is the Senior Raters responsibility to get the eval submitted on time. Hit up your Senior Rater and let them know your eval is late.

Have you talked to anyone in your leadership chain about this?