Hi Antonio,
As far as I am aware, it should be possible to go up to 64 logical cores even if we don't have proper NUMA support yet. On the splash screen (and About box), does Terragen report that it found 88 "cores" or 44? If it says 44, go into Preferences and set the override to 88. Secondly, increase the maximum thread setting on the render node's Advanced tab because that defaults to 64.
I plan to address the NUMA issue, but it would be great to know if you can get your utilization up to at least 64 logical cores.
In any case, rendering multiple instances in parallel will probably be a more efficient way to use that many logical cores. Whenever possible you should try to distribution your animation across multiple instances and limit the number of threads per instance, even after we become NUMA-aware.