In IRROPS situations I've made changes like flying into AMS instead of FRA (destination was actually DUS so this worked out for me) and things like switching between PBI/FLL/MIA, LGA/IAD/BWI and LAX/SNA but that is about it.

Of course it doesn't hurt to ask, all they can do is laugh but the mostly like effect of asking for a re-route to Europe would be "Next!" -- Somebody else would VDB for far less than that.

And you'd have to buy a one way ticket back from Europe (unless you are emigrating) so I doubt you'd save any money.