The return to Side 1 operations for SBC was recently approved, and today ACS/SBC performed its first observations (of Jupiter and Saturn's auroras in the UV) since the Side 2 failure earlier this month.
From STScI ops notes:
"The first SBC images (science and calibration) were acquired today
(Day 051). All the telemetry indicates normal conditions. The first
internal flats and dark frames are consistent with those pre-dating
the ACS Side 2 failure. There may be a small degradation in
sensitivity (on the order of 1% or less at the shortest wavelengths).
More sensitivity data will be acquired in the coming week."