Covering & lifting gray hair with 30 vol?

[Manzanita]

Hello!!
Could you guys give me your opinions about covering grey hair with 30 vol?
My client has fine hair, with 50% aprox of grey, natural level 5, pulls a lot of warmth.
She wants to go a little lighter so that way her gray would be less noticeable. She would be ok about a warm tone. Currently I use 20 volume with 1/2 6 & 1/2 7 level. Her hair color looks like a warm Balayage due to her ends get lighter with time starting on the roots with level 6ish to level 7 1/2 to 8 all the way to her ends . Since she wants to get blonder ( level 9 or maybe 8 1/2) . I was planning to use 30 vol with 8 level and for her full head highlights I was planning to use an ash High Lift w 40 vol or another option using bleach with 20 vol and apply it all over to achieve a level 9 and then tone it.....
Could you please give me your thoughts and/or suggestions about it?

PS I use Framesi and redken

Thank you !!!

 

[AcidPerm]

As she already has tint on her hair, you can’t lighten it further by adding a lighter tint, so you’ll need to use bleach then tone.

 

[JJH93]

I would do a full head of highlights with bleach, does she want her roots completely covered?

 

[Eloise86]

Schwarzkopf have the absolute range for stubborn greys used with 30vol, they have some ash tones too if she would prefer to keep it cooler x