I will ask again: what do you see as the proximate end of throwing the switch?
Be careful with “intention”; it can mean two things: either the second font of the act, or the proximate end of the object. If you mean the latter then it would seem obvious that different proximate ends would be different objects.
In both the case where the intention is to save the five, and the case where the intention is to kill the one, the physical action is identical: the switch is thrown. The consequences are also identical: one person dies, five are saved. The question is: are the objects of both acts the same? Again, this statement from JPII:
By the object of a given moral act, then, one cannot mean a process or an event of the merely physical order…
You cannot describe the objects of the two acts as being the same simply because the physical action is identical. You must account for the the proximate end (“that object is the proximate end”). Now an end relates to an objective - an intention. What is the immediate objective of the person who throws the switch to save the five? It is to redirect the trolley away from the five. The proximate end - the immediate objective - of the person who wants to kill the one is to redirect the trolley at that person. The visible actions are the same, but the objects are very different
It is simple enough to rephrase it: the object, the proximate end, the reason for throwing the switch, is to get the trolley directed at the person on the track (in one case), and to get it directed away from the five (in the second case).
Nor do I think the object is “something to which the act is inherently ordered” because this refers to “a process or an event of the merely physical order”, which JPII explicitly stated was not the object of an act.