To enlarge the target dropdown list …

If you find that the area where you select which post or page the comment is to be moved to, is too small, add this to an admin css file:

/* make target posts/pages drop down wider */
#tako_post_chzn {
  width : 100% !important;
}

/* make list of target posts/pages taller */
.chzn-container .chzn-results {
  max-height : 200px; 
}