For me:
-Full set of emotes/expressions
-Can use combat animation similar to Gpose, and being able to turn off combat effect too
-Being able to rotate 360 degree
-Being able to hide weapon during the edit
-Being able to change class during the edit, which is for Limit Break preview
-Don't require the face in the frame
-Being able to change Accent positions
-Can have more than one accent.
-Fix the bug where glowing weapon effect will go through characters if they are placed behind
-Add effects like being wet and status effects (freeze, sleep)... similar to Gpose
-Instant picture remembers the last picture you use, so that you don't have to re-link it every time.
-The ability to show Instant Pictures in non-Crystal Conflicts content.
-The ability to hide adventure plates/instant pictures from other players when inspecting/joining Crystal Conflicts. Some of these might be quite NSFW, so it is better to have an option to hide when it starts to bug you.
-PvE-based adventure plate/instance items. Beast tribes, Gold Saucer, crafting, dungeons/raids/trails...