Hi lee, the radio renders turned out great!

The fillet limitation is a bug in the v1 fillet mechanism - this is improved in v2, in the current v2 beta you can go up quite a bit larger, up to 0.7 units.

Your front profile is a bit lumpy:





Those kinds of lumps and bumps tend to make things harder on the filleter - you may be able to get better fillet results if you make your cutting curve a bit more evenly smooth shaped instead of with that lump in it.

- Michael