L3 is simply a TM later and L5 is TM with Apical feedbacks. They are just standard HTM layers. I don’t have the expertise to invent my own.
My old post Path anomoly detection using Grid Cells and Temporal Memory compares GC and scalar on their prediction and anomaly detection capability. I can run experiments of the agent using Scalar encoder (RDSE is not implemented in Etaler) if you want the result.