With BRISK, you may adjust the patternScale parameter, which by default is at 1.0 . If I am right, this means that the scale of the sampling pattern for a single descriptor is one time the value hardcoded for BRISK (I think that a 30 pixel wide patch is used by default...).
I am pretty sure I read somewhere that the maximum value is patternScale = 5.0, but I can't find it again. Am I right?