Would it be possible to add a new building/mine type (after some research requiring, for example, Vulcanus Fulgora and Gleba sciences) to force underground attacks to come out of the ground and trigger their attack at the location of this building?

No research required. Any radar or turret will cause the "underground attack" to do this

I was thinking more about adding a type of mine in front of the walls that would become a priority target in front of turrets and radars and would trigger the attack at the desired location in front of the protective wall (hence the idea of ​​limiting it after research so that it is not too simple at the start of the game)

It is possible to make such a "mine". But it is very difficult to balance. If there are many of them, the player will place them everywhere and underground attacks will be ignored from that moment on. If there are few mines, they will have almost no effect, and it will not be worth the effort to develop them.

Also, the very fact of limiting the quantity will look strange at a plant that produces products in the thousands...

I don't see the point yet