Okay, I lowered down the blank/invalid transfers to closer to 5%-10% instead if 20%-25% - which was what I had no parameter to go on and now I still have:
Milei - 50,7%
Massa - 49,3%
Extremely close to a tie, but slightly leaning Milei indeed if he gets that 70% transfer from JxC and 65% from Hacemos por Nuestra Patria.
The higher the Bullrich voters abstain, the better it is for Massa is what I am getting. He needs at least >20% of these people to not pick a side and at least abstain and then overperform only a bit between new voters or voters who initially went blank/null.
Basically, Milei winning depends on how much of the JxC vote goes to Milei. Didn't UCR already vote Massa?