It is unfortunate that two years have passed since the parties filed their respective summary judgment motions and the ALJ has not yet made a decision. Unfortunately, you have no practical basis for getting this logjam moving. It appears your appeal was justifiably dismissed as premature.
FWIW, your situation is not unique. Federal employees often have their discrimination complaints linger for years while judges decide dispositive and non-dispositive motions during administrative proceedings and during judicial proceedings.