Trump doing JRE is huge for Joe, likely his most viewed episode ever. Not sure how much it helps Trump though. I would suggest most of Joe's audience already supports Trump.
I can't imagine Trump doing JRE is going to flip many votes from Kamala to him. You might get a few non traditional voters, people who never usually vote, on board. But I'd suggest the benefit will be negligible.
I don't want Trump to win, but if I did and I was advising him I'd suggest going on Stephen A's podcast. The venn diagram of Shultz viewers, Theo Von viewers, Nelk viewers and JRE listeners/viewers is almost a complete circle. Alot of black people feel disenfranchised and don't feel Kamala will represent them. Trump would do well extending an olive branch in that direction.
But if I'm being honest, he probably doesn't need to. It appears he will win anyways.