Oh my gosh, this is news to me, so awesome. The MC Integration add-on module would also be needed if you want to see this or any other MC CAS feature in all areas of the game, such as Create a Household. Whenever I invoke that, the time it takes to switch categories goes down to next to nothing. You can still see the pre-mades in CASt, but each entire item only takes up one square back in compact view rather than an entire row. NRaas MasterController has a 'Show in Compact Form' option for CAS that collapses all of items in a group (row) into one square - meaning for the items that come in two or three different pre-made recolors/restyles. As I understand it, merging's benefits come into play during the game's loadup routine. If you mean the delay before all the thumbnails load and actually become selectable when you click on the different categories, could be mistaken but don't think that merging is going to help with that.
What I hate is the waiting time in CAS when you click on hairs or a different outfit. I don't care about the waiting time to merge. I'm going to try a big old file and see how it works.
