personally, after looking at many sets, I think ergo user (and to some extent, 40's/ortho) are the type of users that like to mess up with their layout to find the "best" way.
that makes a lot of these common legends are incorrect to use which can be kind of annoying.
this also applies to 65% users with the rightmost column, but usually it can be covered with novelties.
so if possible, i do like the idea of having a custom, semi-nonsense, icon like Atlantis / Godspeed.
This move can also reduce the number of keys per set which will help in reducing the total cost (since apparently, ergo kit for KAT sets are increasing for each release).
that being said, i do like the very clean, simple default icons.