I disagree on this point, as I've discussed in length in my posts on another thread here, here, here, and here. I won't repeat them all here.
In short, the ripeness is the interference with the RNC National Convention where Trump is to be formally nominated. It's no coincidence that Merchan chose the sentencing date to be just before the convention when it would not have mattered to "justice" if he waited two more weeks. That's about six weeks away.
In this case, SCOTUS would have original jurisdiction:
Article III Section 2
In all Cases affecting Ambassadors, other public Ministers and Consuls, and those in which a State shall be Party, the supreme Court shall have original Jurisdiction.
I would think that "The People of the State of New York v. Donald J. Trump (IND-71543-23)" would qualify for an original jurisdiction hearing by SCOTUS.
Trump could argue that his fifth and sixth amendment protections were violated by the district attorney and the trial judge in order to convict him and sentence him in such a way as to prevent his nomination in July, which has national impact.
That's pretty ripe right now with the clock ticking to July 15.
-PJ
Maybe he will restrict Trump to Trump Tower and tell him he can participate in the convention by Zoom.