Similar to Accessed but for the Accessed column to be triggered you must view/edit the entry.
A column that is dated when I copy either the username or copy the password would help me.
There is a last accessed field, but it is updated at the same time as modified so it is meaningless. This is a good suggestion. What are the specific triggers you would expect would trigger a time update?
https://github.com/keepassxreboot/keepassxc/blob/develop/src/core/Entry.cpp#L90
Id say trigger when Password is copied/autotyped. Because sometime I copy the username(my email address) when filling out a forum (not loging in my email.)
Also it should be updated if you double click the entry to edit it in the popup dialog. While editing you also view the data.