I’m pretty pleased with how it turned out, even with the issues.
I had to change the calibration values, so the rough cut didn’t follow the etching. And a lot of the fine details broke off during the cutting.
I’m case or helps anyone else out, the parts that broke were all unsupported, and broke off on the third pass. Nothing that was 1/8 in or larger broke. Some 1/16 in details chipped off, and some survived.
I used a 1/8 in 2 flute downcut bit at the lowest speed setting in the DeWalt dp611 router on 1/8 in 3 ply. Unsupported details smaller than 2mm often break off.
And this works fine for everything I have planned, but if anyone thinks different settings could decrease breakage, it might help someone else out.