A recent change, that must have happened in .0300 or a couple betas earlier (i just tested in .0304 and it's still nonfunctional), the CEA_ListRightClickOnWhite doesn't fire when shift is used anymore, not sure if anything else is affected by the same cause, repro:
then right click the list, w/wo shift.
Also since on this subject, I noticed a couple of SC cea's don't exist, I guess maybe they could be [reserved] and reused if you ever add more cea's.
15 = CEA_ABMiddleClickIcon
27 = CEA_ListLeftClickOnWhite