We're in the process of debugging the LSWA workload to understand why it isn't causing lookaside activity in v4.2.
In the meantime, we should write a simple workload using Python + the MongoDB driver to see if we can get something up and running quicker.
If this seems more promising, we can continue with this approach. If not, it should help us debug the LSWA workload since we're likely to run into similar problems along the way.