Considering the fact that during his four hour deposition Trump took the Fifth 440 times, it is probably best he doesn’t take the stand.
I’ve conducted thousands upon thousands of depositions. In addition, I’ve been deposed several times. It is generally not the “smart” thing to do in a civil case as the jury can make a negative inference from the invocation of the privilege against self-incrimination.
In this particular case, see NY PJI 1:75; NY PJI 1:75:1, related commentary and case law.