If I had to score the debate, I think it ultimately was a win for Trump.
People firmly in Trump's camp will have come away believing that Trump completely owned Biden.
People firmly in Biden's camp will have come away seeing a lying, bombastic, unpresidential clown.
What follows is my own observations about people who say they are still undecided.
The kinds of individuals who could possibly still be undecided are those who can't or won't take the time to do independent research. Often they are swayed by those in a position of power making blanket statements. So comments by the president last night regarding the fact that Biden would have had 2M dead due to corona, or that Biden will usher in a wave of socialism otherwise he has lost the left, or that Biden finished last at a college he can't remember, will all leave marks. They have already proven the willingness to give the president the benefit of the doubt. They have already shown that they are unwilling do their own fact checking. I keep coming back to the fact that when talking to people who say they are undecided and you start digging into their reasons for being undecided, it is largely a recitation of Fox News talking points. I am shocked by the number of times that I hear "Hmm I didn't know that." or "That can't be true, I saw it on the news." Generally they have tended to be older people who make good wages, are retired, working but aren't really affected by coronavirus, or have a very nice standard of living.
Due to all of the above, I am more with CA. They may not like the moron currently in office, and they desperately are hoping that they are given a clear cut reason to not vote for him. However the only places they are willing to go to try and find a reason are either Fox News or Facebook.
Whether a new debate would help or not, I am more of the opinion that if Biden doesn't debate again, he will be portrayed as scared of Trump, which will play into Trump and his supporters' strongman fantasies. If he does debate, it will be just as bad as it was last night, but at least he won't appear to be conceding the presidency before the election is even held.