Initial timing

The VA is adjustable, and any reading I've done states that altho it is adjustable, the "amount" isnt adjustable, it's the "when".
I wonder if now because I have my initial at 15*, that the VA is killing it and I need to adjust the VA?
I can swap the VA to the 8.5, but curious if it is simply an adjustment?
The 11R VA holds vacuum
defective part