Channel 2, bulk cap on back side plus high freq cap on the front. No changes to the output side.

Input ripple is greatly improved, ranging from 21 mV p-p / 0.86 mV RMS to 33 mV p-p / 1.7 mV RMS.

Output ripple is only slightly improved, hovering around 19 mV p-p / 4.65 mV RMS regardless of load.

So the high freq cap had a massive impact on input ripple, but fairly small improvement on the output side.