3.5 hours to transfer is more than enough time. The foreigner immigration line can take time (I’ve done 1 hour waits a few times, also 5-10 mins many times) but that’s usually a little later in the morning (8-10am arrivals from USA) and getting bags and customs is like a couple mins at most. Not worth the transfer to AEP, it’s a long drive (45 mins or more depending traffic), unless you have a crazy hours long delayed flight you should be fine.