Trump is engaging in weird posturing about this. He’s a defendant in a felony trial, and is at the disposal of the Court like any other felony defendant on trial. There’s no general expectation, to say the least of right, for any party, to say the least of a defendant in an unrelated criminal trial, to appear at an appeal. (They are usually attended only by counsel.)
What this does underline is that if Trump is convicted he cannot expect lenient release conditions. 24/7 home confinement in New York with an ankle bracelet, except to the extent necessary to attend other trials or medical appointments, is to be expected. Denial of access to electronics except to call his criminal lawyers is a real possibility - meaning no taped or live video at rallies or the convention, no television or radio ads, etc.
Good luck with that. For the Supreme Court to accept a corrupt state judge can order the nominee for one of the two parties cannot campaign.
Re: 64 - you could be correct about possible home confinement conditions; those would certainly subject to appeal.