You've asked the key question. Will SCOTUS grant cert. They don't have to hear this case.
If they won't hear it timely as an emergency request then why would they wait until after the election?
If Forrester wins the issue is somewhat moot though capable of repetition. If Lautenberg wins then SCOTUS gets involved in a somewhat political decision which SCOTUS does not like to do.
SCOTUS punted this case because it doesn't need the controversy so close on the heels of Bush v. Gore. I don't like it either but it is the reality. Forrester must win at voting booth.
You have missed a main point of this thread. There is a HIGHER standard of proof in the US Supreme Court (and in all other courts for that matter) to grant an injunction than to rule on any case in an ordinary time frame. Also, granting the injunction in the US SC would have required five Justices to vote in favor. Accepting the case for review requires only four Justices to vote in favor. Add the fact that the Supreme Court suffers less institutional embarrassment (maybe) if it decides this case after the election.
The bottom line is, as I said, that it is more likely that the Court will take the case in due course than it was for it to grant the injunction.
Congressman Billybob