This is because they were from the first cards with install effects ever.
(Core 1 #35 for Modded, and Core 1 #60 for Mirrormorph).
Usually, when this comes from Archives/Stack, it is said clearly, so I won’t continue to seek something in this direction.
I still “beleive” this is CDE but I have to admit both explanations stands.
It’s strange, because if it were A+B, there is actually simpler way to explain this, like texts inspired from Caprice mixed with AG :
“Once per turn, whenever the Runner passes all of the ice protecting a server, the corp may install an ice in the innermost position of this server at no cost. The Runner approach that ice.”
Now they got that quantic text. That’s a build-in-nerf conspiracy ?