1) Penetrating oil for 2-3 weeks - nothing changed
2) Heat - again nothing...
Alsways tried with 2 nuts tightened against each other, but it was not possible, they started to turn together before the stud bolt shows any sign of getting loose.
Finally i got all out by welding a nut on it and then cool them down with ice spray and oil + impact wrench.
Just one cracked - a friend took it to work and needed 2-3h to get it out on a milling machine without damaging the thread (i don`t like helicoil inserts).
Now i have ordered 2 types:
Hazet 844 to get them out without damage, but not possible to use the impact wrench:
Stahlwille, which will damage the thread anyway (just in case if the Hazet will not work):
Both types will not apply any bending load on the stud bolt if they are used with a T handle (that was priority 1 for me).
What i also want to try is to heat everything up to ~150-200°.
The theory behind this is, that there is this white "rust" (aluminum hydroxide) because of electrochemical corrosion.
This material fills up all gaps between aluminum part and bolt with pressure because it grows in volume.
By heating it up, aluminum hydroxide can be turned into aluminum oxide with a smaller volume that will help to loosen the bolt.
But this is theory... and my fear is that it is not possible to heat it up high enough without damaging the aluminum
maybe more interesting is the thermal expansion (aluminum expands twice as much as steel).
40 stud bolts are waiting to get removed (hopefully a full set without damage and not one cracked)
)
Motivation, motivation !! 
