Hey Jack,
It'd not make a massive difference, I don't think I would be able to tell on the track if I am honest - its important that the angles are the same which you say you have, so it should be very good.
Packs of shims are available, not expensive. Will look up the Part number. I ordered 2 packs with my car and all is good. Check the kit bag which had the Lipo brace, as you may find enough additional shims in there (intended for spacing of cell brace).
Chris