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Many of the most striking differences at the digi level can be tracked to when I started using the LPM updated physics model in the system tests. Compare the ACD and CAL digi plots for the current version against v17r17 (stats page) and v17r17LPM (stats page) GR v17r17LPM Report.
The dramatic shift in the TKR digis comes from the occupancy update that went in at GR v16r1.
The more recent tests now apply the flight01 geometry, but that seems to have a less dramatic impact. See system tests for v17r35p20 (default, ideal calib flavor) and v17r35p20_geom (flight01) to compare.
Changes
Most notable changes may be in the systests/default config to use LPM updates in the physics model and to apply the flight01 geometry.
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