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The overall level of digis is reduced for the later GR versions compared to v17r7. I think most some of this for the ACD should be because of the updates to exclude sub-threshold ACD tiles for PT events. The ACD hit status bits were added to ACDOverlay in v17r10.
A change in v17r13 is the handling of merging overlays into empty events, pure overlays. This should reduce the general level of digis.
Additional Overlay tests?
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