Actually just specifically for burns it might be better not to review, because then if you actually wouldnt have remembered the word or its reading, once its burned you cannot review it again. But for the others I would look a word up once in a while if im reading something and I forgot the kanji. But I dont actually go around reading everything before im about to do my reviews though. The point of the srs is to make you review something you dont know properly more when you dont know it well enough anyways.
Congratulations!
I am also on level 12, and hoping for first burns sometime soon. I have so many in the enlightened pile that it seems like it should be right around the corner. I started in March this year.