Hm, I hadn't noticed that before, but I can confirm exactly what you're reporting. Worse yet, the layer mask doesn't actually take on the rounded value (it's left at whatever fractional value was in the field before hitting Return).
I can't imagine that's a feature. Edit controls just don't work that way in general.
I think someone at Adobe must have missed removing some rounding logic in the edit control when they made the function capable of handling fractional values.
Or someone put in bad rounding logic...
It was working just fine when the fractional radius support was added and tested (ages ago).
Yeah, that's a bug (even though pretty minor).
Hi Mr. Cox,
thanks for taking time to check this. A fix sooner or later would be nice :-)
With kind regards