Is it possible to make -jN dynamic based on CPU load?

For example, would it not be beneficial to have -jN > nrcpus during the configure phase, where CPU load is low? Then have -jN = nrcpus during compilation, where load should be evenly distributed to each CPU? How difficult would this be to implement in a build environment? Would it require changing each configuration file for each step? Is it possible to automate for multiple projects, given they use the same "make" program? This is assuming that the workload is never I/O bound.