Not specific to neosemantics but we generally do not recommend setting min/max heap to differerent values,
The heap memory size is determined by the parameters dbms.memory.heap.initial_size
and dbms.memory.heap.max_size. It is recommended to set these two parameters
to the same value to avoid unwanted full garbage collection pauses.
and also, we generally do no see where customers set max heap to be over 31G.
How did you arrive at a min and max heap of 2G and 55G respectively?
Further you have not defined dbms.mempory.pagecache.size where this parameted is used to defined to describe how much RAM should be allocated to record the graph structure in RAM. If not defined it will default but we generally see where customers explicitly define.
The doc reference above provides some good details as to these parameters