This is part 3 of an Idea submitted by @KPerison http://forums.autodesk.com/t5/infraworks-360-ideas/horizontal-vertical-editing-of-design-roads/idi-p...
"In order to facilitate quicker edits of the horizontal/vertical components and reduce the amount of realtime regeneration the model has to calculate please incorporate:
3. Disable dynamic update of the model when editing Horiz/Vertical alignments until the user is finished making edits, then update. Allow user to toggle dynamic update on/off or manually start an update."