Tip: When you are changing the grammar, it's better to disconnect it. Otherwise sometimes it may detect there are illegal grammar and then crash.

To be able to use this node, we need some new features from 5.2 version which are already merged, so don't worry about that. You need find  the preference-System-Memory&Limits-Geoemtry Node Stack Limit and set it to a very high value like 999999. Otherwise this node maybe stop earlier than you expected! And then enable the experimental feature: Hair Dynamics.