RC-2 QUESTION, Quick response?

Hi I was thinking of buying an RC-2 loop station from Boss.....now I really want to change phrases....ive heard from some places that you can plug a FS-5U pedal by boss into it to change phrases while playing live but then other places say you cant and that an extra pedal can only be used to change tempo (which does make sense as it says Stop/Tempo on the RC-20 itself)....So can anyone confirm whether you can change betwen phrases using an extra pedal? And I mean the RC-2 the small one pedal as opposed to the double RC-20XL.

Thank you....(and sorry about asking for a quick response just one on ebay I want is going soon lol)