The history of the design is that in the Seduction I originally used 0.033uF caps, with the second cap being 0.010uF + 0.0012uF in parallel. (The two RIAA caps are very close to 3:1 ratio). Precision caps (i.e. 1% or 2%) are not available in as many different values, so even that was hard to find - in the end we just used 5% caps.

In the Reduction I switched to 0.030uF and 0.010uF since multiples of 10 are almost always available in precision lines. By paralleling three to get the 0.030uF, you need 8 identical 0.010uF caps. Usually there is a price break for 10 caps, so if you have a capacitance meter you can select the best 8. In fact, by paralleling the outliers carefully, you are likely to be able to get excellent precision even with 5% caps.

Of course, few (if any?) ever took me up on this option. :^)