Been pondering this one since yesterday.. A few questions to clarify ? What are you using the radius gauge for ?
- ordering a radius block to shape the frets for levelling ?
- setted up the curve of the bridge ?
- other ?
If it's setting up the bridge, things to consider;
- the lower strings (E+A) occillate further when struck, so they require greater height from the frets (That said, playing style comes in here i.e. how hard you pluck the string).
If you choose the 10 radius, that will tend to leave the middle stings higher relative to the lowest and top string when compared to the 12 gauge.
If you choose the 12 radius, that may allow you to leave the middle strings a little lower with a tad more space under the lowest string.
However, it's a compromise, as other things will influence your setup, such as levelling the frets.
Have a play and see what each feels like. Whatever happens, good luck and I hope you enjoy the experiment. While you have the gauges, you can always undo something if you don't like the results.