Using 10, 20, etc. is more symmetrical with 01, 02, etc. So, if symmetry is the goal, it seems to be the better alternative.
That side's not the problem. The problem area is 12-13-14-15 vs 22-33-44-55.
One alternative, though, which you may find more symmetrical, would be to use 10, 20, 30, 40, 50, and 60 instead of 11, 22, 33, 44, 55, and 66.
That would change 22-33-44-55 to 20-30-40-50, which is much better and does reflect the other side of those diagrams. I'll give that a look on a fuller diagram later, along with how things look from the Opposing Faces. It may satisfy both sets of needs.
Being bigger, the outer cube uses bigger numbers.
It isn't actually bigger. It only appears bigger in that projection.
That side's not the problem. The problem area is 12-13-14-15 vs 22-33-44-55.
That would change 22-33-44-55 to 20-30-40-50, which is much better and does reflect the other side of those diagrams. I'll give that a look on a fuller diagram later, along with how things look from the Opposing Faces. It may satisfy both sets of needs.
It isn't actually bigger. It only appears bigger in that projection.