May not be a bug, but unless I am missing something this is an unwanted change to the UI.
What is the last version to allow animation time to be input in seconds?
M/S is a unit that I have no way of matching in another animation package, which I do quite a bit to add items enscape does not offer such as animated objects and textures.
If you would like to improve this, it would be far more useful to be able to input segment time in more than on format... speed, seconds, or frames. The slider could be for one of them, and also allow us to type in any of the others.