I am trying to figure out how to get the 'Last Interaction' Button to show up in an OOB system without modifing the condition.
Not sure if this is helpful but for display options I always leave the Condition field alone.
I then put the condition I want in the User Condition field. This way, the User Condition overrides the Conidtion but I still have the original condition there in case I ever need to refer back to it.
In this case you could put true as the user condition if you always want it to show up or you could do something like
index("SysAdmin", $lo.ucapex)>0 // only visibly by admins
index("service desk agent", $G.role)>0 //only visible by service desk