Oh! Major UI issue! When sending an email, if you include a signature, the signature stays fixed at the bottom of the email/comment text input area, and scrunches the text up into a teeny tiny scrolling text area. See picture. Notice the itty bitty scrollbar on the right. It's caused by the signature below it (not shown in picture for privacy).
In v2, the signature would sit within the text area, and would scroll along with the content, not sit fixed below the text input area.