Affecting multiple bones with PyConstraints

I have been looking at using PyConstraints scripts with bones recently, and it all seems fairly easy and intuitive; however, I am looking for a way to constrain multiple bones with the same script. An example is the IK constraint, which operates on a chain of bones, the length of which can be chosen. I can currently only see a way to affect one bone with one script (the matrix object returned from the doConstraint() function). What I want could be done to some extent by splitting my constraint into several scripts and applying to the chained bones manually, but this is less than ideal.

I appreciate that constraints are designed to be generic, and so dealing with matrices rather than bone objects makes sense, but I would really like to know if what I want to acheive is possible.