Wella Blondor & Pro-Oxide 9%

Hello!

This morning I bought a tube of Wella Blondor Soft Blonde cream bleach and some "Pro-Oxide 9% Creme peroxide" (it's not the Redken stuff, just a very cheap trade only developer) for doing my roots, as Boots in Ireland seem to be not selling BBlonde any more! (Either way I wanted to move away from it and use better bleach in general.)

Just wanting to make sure these will be fine together, and the the "Pro-Oxide" developer is ok (it was very cheap and I'm starting to wonder if I made a mistake getting it!)

I read on the instructions you can mix the Blondor 1:1 or 1:2, would it be better to use 1:1 to get a good lift? (I want to use as little of the blondor as possible as it's quite expensive.) I have level 3-4 (more on the 4 side) roots, and with Jerome Russell BBlonde normally gets my roots to a light yellowy blonde (but not light enough to tone to white) in 45-50 mins with 9%.

Thank you!