All a short term trip to jail would do is play into the Martyr complex that he and his supporters have. He would complain that he’s not getting a fair trial, and low-information voters who are not paying attention will believe it.
While the judge doesn’t care about Trump’s political prospects, he does care that the trial is fair and that public perceptions don’t make it into the jury’s deliberations. But marching Trump off to a holding cell will be such an event that it would be impossible to keep it from the jury, and could give Trump a valid avenue for appeal.
However, if the judge establishes a paper trail that proves Trump was given every chance to comply, then it would make it harder for the appeal to succeed. Trump can’t very well argue that the court is biased against him when they gave him extra opportunities to comply.