A commit message text box and a code review text box does not have any scroll bar, does not allow scrolling with a mouse and does not allow Ctrl+A (select all text). All these things would be useful.

This suggestion has been added here already (https://plasticscm.uservoice.com/forums/15467-general/suggestions/4341465-checkin-comment-and-code-review-text-boxes) but it was marked as completed even though it is still not working.

See also the original post here: http://www.plasticscm.net/index.php?/topic/1291-some-ux-issues/#entry10137
There is also another suggestion close to this explained by a picture (partially displayed lines).