I've been thinking, and the preliminary result of this cogitationary practice looks like thus:
Emergency Smarts: 3d6 Aid INT, Delayed Return Rate (5 points per 20 minutes; +3/4); 52 APts; Standard Effect (-0), Extra Time (One Turn; -1 1/4), Self Only (-1/2), No Concious Control (Only When Exposed To Danger; -2); 11 RPts.
Plus
PhysLim: Near-Human Intelligence (infrequently, slightly).
This last one is a variation of the PhysLim found in the Bestiary, and only comes into play when the Kafer's not INT boosted.
I think this is the most accurate -- and easy -- way to portray the abilities of the Kafer as written; one could do it as a Multiform, but that is just too clumsy, IMO . . .
Edit: Edited a math problem . . .