In the decades I've been coming to Argentina probably 10+ times
They are apparently "cracking down" now but we have heard this narrative for 20 years. And since someone will inevitably reply with "No, trust me, this time they REALLY mean it" we have also been told "This time they really mean it" for 20 years. So it's up to you, no one can give you a correct answer.
My advice would be take the last ferry back with the company that docks in San Telmo near the edge of la boca as its often late and I know for a fact the customs officials just want to get the hell out of there and go home. They aint doing 2 hours overtime to deport / detain you. I've literally had they guy reach over the customs desk, yank my passport from my hand, smash the fewest buttons possible on his keyboard then shove my passport back into my chest and tell me to move