Hi, there. The decision to change away from using the space bar for the shortcut had to do with supporting accessibility browsers and devices, such as those used by visually impaired users. The space bar is one of the most commonly used keyboard keys for accessibility functions, and since Roll20 does not currently have mappable shortcuts, we wanted to better support those users. Just wanted to pop in here and explain why it's unlikely that the space bar would be reinstated as a default waypoint marker shortcut. Meeting this request in other ways, perhaps through an API option or user-mappable shortcuts, might be something to look at, however.