Inability to accumulate minor anomalies?

It is not a problem, really, just that the system will see those transactions as happening at the same point in time, which should be accurate enough if you are looking for anomalies at a larger time scale.

The “HTM score”… what is that? Are you talking about the “anomaly score”? If so, you should certainly try using the anomaly likelihood process as well. Here is a post where I tried to explain how to use it: