My kensai sit at lvl 25 atm , dualspec it?

Hi , started bg1 with kensai/mage in mind, just completed bg2 Soa at lvl 25 kensai , has been so fun as kensai only in my soloing, now im wondering , should i dualspec it? ye ive heard all the babbling about doing it at 9 or 13 .. what if i do it now? , or even at 30 ? , gimme ur thoughts on this, gimme some tips, and if u have dualspecced it later then 13 u are more then welcome too share ur opinions. my goal is bg1 all the way too icewind .

flamers be gone .