Michael,
I slept on this a bit and thought I would bring it up again.

doing it that way may make your ui unpredictable. I used your question method on myself. "What happens if someone chooses 6 decimal places?"

It does break the basic continuity from function to function. My only initial problem was that .54 displays as .54, but .5407 displays as .54 and I would need to edit to be sure.

I think you had it right with keeping that number simple and only have the larger value in the edit popup, but that label could have some king of an "identifier" that means there are further digits in the realm of the decimal options. Does that make more sense? so like color or a character. Somthing like .54>

Burr

[EDIT] A possible try I was thinking of also was to make that decimal display in the label only work off of "1 digit" to the left of the decimal (possibly even "no digits" on the left). Again with 12 inch parts the thousanth value is less of a factor but with the 1 inch and .25 inch stuff it can become apparent.