There really is no way to filter this. You may have also noticed that you may get two readContent entries just for some user downloading a single file (even without progressive load).
This circumstance is why I ususally do not use alfresco-access. I prefer defining my own audit application. This enables me to also implement some kind of consolidation / cleanup job that aggregates audit events asynchronously to simplify the data structure and eliminate potentially redundant entries. Doing any post-procesing on audit data requires low-level Java programming and can be a bit complex. Usually you are mapping data from one audit application to another, and deleting the original entries when done. I use such an approach e.g. in my generic audit addon for tracking "active users".