My thought process is if I can get the subframe off I can hopefully weld that stud from the underside of the body with subframe off in hopes that will keep the stud solid and in place

I managed to after a lot of heating and patient and easy pushing with the breaker bar remove one of the 2 bolts. Tmmw I plan to see whether the same approach will remove the second bolt.

Then wire brush head and penetrating fluid the heck out of the remaining nut and with a.vice grip hopefully wiggle it loose and then with the appropriate guidance weld that stud back to the body