In order to full use this as a UX professional, I would have to have the ability to include gestures, most critically for handing a stakeholder a wireframe or design. Gestural swipes, two-finger zoom, force-touch, etc. Otherwise I don't think too many experience UX professionals will be able to properly communicate core functionality and the behavioral imperatives incumbent to the process.

Most of modern apps have some custom behaviour - for example

In user profile, you see big profile picture, but when you scroll down to see user posts - picture gets smaller and moves to the corner.

Would be cool to be able to treat scroll position as kind of keyframes timeline, where you can modify styles of some elements and tween them depending on how much some view is scrolled.

Some tools have kind of similar option - https://www.youtube.com/watch?v=jRHuAq4PqQo - check first 30 secs.

I'd like the ability to crop a section of a prototype when recording.

For example, if I want to record a video of clicking through a form, I don't need to show the entire layout — just the relevant section.

This would result in a better visualization tool, as well as smaller video or gif file sizes.

1. Ability to have a single object (or group) break out of its artboard and cross multiple artboards within a single prototype. The simplest use case is the creation of a global navigation bar that spans across multiple screens. This object's interactive elements would also work across multiple screens as well, and any edits to this object would update across the rest of the screens.

2. Easy interaction management and editing. Also provides consistency with consistent elements within an experience.

Support for native device functions (e.g. Cordova).

Example dropdown selection, media players, maps, etc.

This would increase the demo's effectiveness and allow for a more real-world prototype.

Support for simple animation.
Example: Show/hide a slide or push menu

This would enhance a demo and engage prospects that are familar with common application patterns.