I'm trying to decide how long the cutting edge on a pattern router bit should be. I'm trimming a 2-by (1-1/2" actual) with a pattern / template on top, and I'm having a hard time finding a 1-1/2" (cutting) length bit. I found a 2" length. Is there a reason I shouldn't just use the 2" length? I can't find any technical information about selecting the appropriate length, or whether I should avoid a longer length.
P.S. I'm aware of the stability considerations with shank diameter; that's not what this question is about. The 2" length bit has a 1/2" dia shank.