Gradually going lighter with Prism lites? Advice appreciated (PIXS)

Okays so I'm still trying to achieve that pretty Ashy beige Balayage look but my hair is still too dark so I want to gradually lighten up. So when the salon did my hair it was too orange so I put blue in it to neutralize it. I'm planning on waiting 4 -5 weeks before I go lighter with the highlights.

The plan is:
Step 1:  balayage the highlights with saloncare Prism Lites blue + Saloncare vol 30 developer + Olaplex 1 mixture
Step 2: 20 minute treatment with Olaplex treatment 2
Step 3:  add Ashy toner for 10 minutes
Step 4: shampoo with  purple shampoo and condition with Olaplex #3

My only concern is using the prism lites. It really does the job and lightens my hair level quickly, but maybe too quickly? It's fast! but I like that it adds cool tones to dark hair. I have thick hair so I'm scared some areas will look lighter than other parts since it bleaches the hair so quickly. Any advice for which bleach we should use instead? I already have a gallon of vol 30 developer and prism lites thats why I wanted to use it.

Ashy Blonde will take to many treatments so I'll be happy with a ashy beige. I just  don't what know which products will be best. Maybe Fanola 9.11 + vol 20 + no yellow shampoo?

This is my hair after the salon

This is my hair after I neutralized the orange tones

And these are the color I'm eventually trying to get to