When importing meas_mosaic, the coordinate system for writing out the wcs/fcr files was not adapted to that expected from LSST (which always associates the detector origin with the electronics, whereas HSC's is such that a given detector's origin, pixel (0, 0) is associated with its LLC w.r.t. to the focal plane), but rather the tasks in meas_mosaic's updateExposure.py were adapted to account for the rotated CCDs. It was assumed that this was the only place those corrections were every used. This turns out not to be the case since the wcs used to create the coadd gets attached to it in coaddInputs. If meas_mosaic was run and doApplyUberCal=True (which are both the case for our HSC data processing), the wcs’s that are getting attached to the coaddInputs are not in the coordinate system appropriate for LSST for any nQuarter != 0 ccds.

Since this is already causing an issue in pipe_tasks's propogateVisitFlags.py, see issue highlighted in DM-9383, (and could very well be causing issues elsewhere as yet undiscovered), we have decided these outputs need to be written out in the coordinate system expected by LSST.