Hello, thanks for the repro. I think what is happening is that the setting Snap to the Interval is forcing the key you paste at 0.99 to be pasted at a whole integer frame (ie. 1.0).
We’ve been looking separating Snap to the Interval from Snapping altogether so that Snapping deals with snapping keys and sections to other keys and sections and not so much about keeping things on whole frames. We will be removing Snap to the Interval from this menu and adding a separate button Force Whole Frames which will allow you to toggle that behavior. With these proposed changes and your repro, if I turn OFF Force Whole Frames, I can successfully paste the key to 0.99 without having it jump to 1.0.
Hope this makes sense and is an improvement. I will try to revisit this thread once the changes are in.