Willem,
There are some immediate alternatives:
1) If you don't expect a lot of concurrent jobs (e.g. less than 36) you could submit the makeflow as a pbs job using -Tlocal as the batch system. In that way makeflow executes in the compute node and all its rules execute locally in that node.
2) With some little changes perhaps your makeflow can be adapted to use the Work Queue (-Twq) batch system. The idea here is that the pbs jobs are work queue workers (one worker per node) that connect back to makeflow. Makeflow then sends rules to the workers available. Some changes may be needed, as Work Queue does not assume a shared filesystem, so you may have to be more explicit about the pathnames, and also about the resources each rule uses (e.g. you may have to put a CORES=1 at the top of your makeflow so that each rule uses one core. otherwise one rule would use the whole 36 cores in a worker).
3) Finally, if your makeflow has a natural hierarchy, you may be able to define submakeflows, with each submakeflow executing in a whole node. For this you would need to use the JX syntax for makeflow, as explained here:
Please let us know if any of these solutions would be suitable for you, and we can explore more in detail how to adapt them to your workflows.
Ben