Let the guy have his court battles so that the right doesn’t complain for the next 4 years like the left did about Russia collusion. It’s an unneeded distraction and if it can be purged from the public discourse before electoral votes are officially allocated then all the better.
They're going to complain anyway.
The sort of people who believe in this sort of conspiracy theory nonsense aren't going to be placated by a court decision. They'll just use it as further evidence that "they" are up to something.
What Trump is doing is dangerous. The concession speech is an opportunity for the outgoing President to congratulate his opponent, thank his supporters and be gracious in defeat thus helping to heal any divisions between the two sides.
But Trump can't be gracious. His fragile ego can't stand the thought that he might have lost. So in his mind he didn't lose, he was cheated. And that just inflames the tensions between the two sides. It's dangerous stuff, potentially.