Nice table, but if you limited the Capacitor values to those dozen or so X2 values available (eg 10n, 22n, 47n, 100n, 220n etc, etc), you'll be able to pick the one closest to your current requirement. No point in having a 290n value when you can't buy one, and putting heaps in parallel negates the advantages (cost, size and weight) of a transformerless design to start with.