Ok I am gonna report back my experience as a long story. Conclusion if you don't have patience for that long story, is that: transit in US with tight schedule should never be an option.

The other day I asked in other thread for advice for transit under 1hr55 in JFK for LIM-JFK-HEL, a ticket sold by AY as the first option if you search LIM - HEL.
Like everyone here warned me , missing the connection is quite possible.But because my schedule again changed and one night delay at worst is OK so I thought I would bite the bullet. Gosh how naive I was and the reality was way more brutal than this.

LATAM flight was DELAYED 10mins departure from LIM, and landed 30Mins LATE at JFK due to traffic control. I rushed to get off the plane before everyone else and when I entered the immigration in T4, ZERO passengers there (There was MPC lane btw). 2mins I passed it, but waiting for luggage arrival still took the time. By the time I reached AY desk in T8 it was missed 10mins. Then I was asked to go back to T4 LATAM desk to get assistance because not a problem caused by AY they won't help. But T4 LA desk by that time already closed from 10pm. So I was left without assistance but to deal with it on my own.

Real disaster from then on. It was the 3rd day affected by Croudstrikle IT thing, and there was large scale of delays and cancellation from Delta (that was reason no one in T4 immigration actually). And booking.com was suffering issues with last minutes bookings nearby JFK it stoped refecting real time capacity so you have to call hotel to make sure there is capacity. So I called more than 30 hotels for an hour, everywhere was fully booked. And I spent over a hundred bucks in taxi heading into town to just get a hotel to stay (not to mention I was turned away from the first hotel in town, because their system was also f* by Croudstrikle and it was booked full even though my booking payment went through in the first place) . By the time I got a hotel and touched the bed it was 3am 😮‍💨.

My other peers who took the same route a week later who know nothing about transit in US getting through everything without problem in 1hr55.

Lessons learned: it is doable for a tight transit in US, provided that everything works ON TIME without SURPRISE. AY sold LA ticket as part of their flight but it wasn't a code-shared and if anything happens AY doesn't give a word at all. I get the reimbursement by LA in the end, although LA was reluctant because 10minslate departure was nothing and 30mins late arrival was also out of their control, until I pointed out that this transit was below the minimum MTC in JFK, and I only asked for accomodations/taxi/food reimbursed not something extra (the expensive call bill is fortunately covered by my company) , then LA agree to pay. And I am still waiting for the money arrives into my bank account until today.