V4: Solder leaking
In a recent batch of the V4-0 test series, we discovered that I2C and IC7 thermal pads on the bottom layer were partially covered with solder that leaked from nearby resistor pads. This happened because the holes in the solder mask were enlarged during production, removing narrow bridges that were separating the pads and preventing solder flow.
Verify with the DEM/manufacturer what solder mask expansion/sliver values should be used to avoid such situations in the future and possibly fix the PCB in a later release.