I think I already tried it. I am not certain, by the way.
[EDIT] The results I received are quite strange: The 0.5 damage factor was more effective than the 2.0, but the 0.1 was the weakest of all. The damage it did was minor, I could recharge my shields completely in a Horus between savloes.
[EDIT2]

I set the subsystem damage scale to 0 and it destroyed all my subsystems on the first shot. It is even stranger that it was as effective at 0.2 damage scale as the previous version with 0.0. Something is hard-coded in the beam damage system.
[EDIT3]I had this setting:
Fire Wait: 3 ; 5
$Damage: 60 ; 13
$Armor Factor: 0.33 ; 1
$Shield Factor: 1.00 ; 3.2
$Subsystem Factor: 10.0
Result: It did not inflict much damage at my shields(only very minor) and it did moderate damage at my subsystems, but when I was hit for the second time, my hull went down to 3% in a Thoth and a second.