The 'recurrence flow' and 'recurrence lacunarity' measures proposed in
https://doi.org/10.1140/epjs/s11734-022-00687-3
https://doi.org/10.1007/s11071-021-06457-5
could be added to RecurrenceAnalysis.jl.
Python implementations for both already exist and could be helpful:
https://github.com/ToBraun/RECFLOW
https://github.com/ToBraun/RECLAC