A slider updates from feedback exactly
the same way a gauge does.
But if you want to show the slider state locally before the
feedback is received, then you enable simulation mode.
But then if you ONLY want to show real feedback after the slider
is released, you might have to do some more work - only parse the
feedback from the slider whilst the sliders digital join is low
(so whilst the slider is not being pressed).
The existing Crestron solutions don't offer this option, so you
would have to craft it yourself with some JavaScript.