He'll never testify. He'd perjure himself within the first minute and likely provide testimony that would, in turn, constitute a basis for additional criminal charges. He's every defense attorney's worst nightmare.
He's a despicable, destructive person who isn't worthy of serving as town dogcatcher. He's already undermined Americans' faith in our electoral system. Now he's taking his wrecking ball to the judicial system. He's made a mockery of the system and has extended a giant middle finger to the judges, prosecutors and other law enforcement involved in his cases. He's even put family members of court officials at risk. He keeps violating the gag order and is basically daring the judge to fine him or put him in the slammer so he can fund-raise off his martyrdom. Even mob bosses don't do this. He just doesn't give a shit about anything or anyone other than himself, and he'll burn the whole thing down if he thinks that's what it takes to avoid a conviction and/or a sentence that includes incarceration.
I'm with Mark Cuban. I'll vote for Biden over this trash even if Biden is receiving the last rites.