Is it OK to use large spacer if I do a lot of track? I currently have OEM 5mm spacers all round which are fine but the rear don't fill in the gap much(gen 2 alloys)

My garage says as I track do not mix size of spacer and keep to the same size all round. He had recommended 7mm Ruf all round.

What's people experience.

 

Prob wasn't clear enough in my post.
I went against my garages advice as thought 7mm all round wouldn't be that different to what I have now. Also thought it can't be that bad to mix spacer sizes as almost all the research shows that most owners have done a 7mm and 15mm set up
I went for 14mm h&r in rear and kept the 5mm as don't want to stick out to much.
Do I now need to do a geo?

 

btw I'm on gen 2 turbo alloys on a gen 1 car.