Would the devil’s acceptance of Jesus as the Sovereign will accelerate the return of His coming?
I read the title question as "Does Satan need Jesus' love and forgiveness to be saved?". Well, of course, everyone does. The issue with this question is, Satan has chosen to reject that love and forgiveness from the foundation of the world. He does not want to be saved. He just wants other people to also suffer like him.
In Revelations, it is prophesied that after Jesus return, but before the final judgement, Satan will be bound for a time, and then released some time prior to the final judgement to again tempt and seduce many people.
This makes the question in the body a hypothetical one. Also, why would that accelerate the return of Jesus? First of all, without a devil we are still capable of sinning, otherwise how could we be made responsible for our actions? Second, the time when Jesus will return, while being unknown, seems to be a time where men are exceptionally bad, not exceptionally good. Third, nothing will "accelerate the return of His coming". He will come one day, that is a fixed time. The prophecies we have tell us about what the world will be like at that time, are maybe meant as signs that the return is nearing, but should not be understood as triggers that we can or should somehow work towards.