Can someone from Cakewalk please confirm or deny this?
As you probably know, the Bakers don't watch the forum that closely. If you really want this fixed, you'll want to file a formal problem report. Even though one decimal point is probably "as intended" for this release, I suspect they would probably get it fixed sooner rather than later, since it was better in earlier versions.
I can check it, but it seems pretty clear you've confirmed it won't do 3-decimal place precision any more.
A workaround might be calculate the new end point yourself, and drag-stretch the clip it to that point.
EDIT: I checked it out. It seems Bigdogs is right... and then some. Not only can you enter a precision of three decimal places, you can enter as many as needed to get 1-sample precision, and it will stretch to that precision, even though it will only display 1 decimal place in the inspector when it's done. Slipstretching also works.
If you have an example of a particular stretch scenario that didn't give you what you wanted, please post exact numbers (e.g. start end, new end, expected stretch percentage), and I'll try it.