spinning wheel when manual entry

This new interactive interface is magical. There is one small hiccup in the slicer: when preview is on, if I key-in a number for the hop size, let's say 128, it starts computing with 1 as soon as I press 1 (before I can press 2-8 and enter) so I had to force-quit Reaper. I presume there is a way to update less often the preview or something but I just wanted to let you know.