Comment by doctorpangloss

This is from my point of view as an experienced developer and VFX artist, including in-depth knowledge of AE.

    A 30fps limit is surprising
    23.976 as an fps does not seem to be dealt with gracefully
    Clicking report bug should take me to a bug report form with info
    Interacting with "rectangle" is surprising because the corners aren't draggable. Probably should default to full size
    I should be able to wind input fields by clicking and dragging on them, such as for rotation
    When I drag keys around in the dope sheet, and let go with momentum, they appear to keep moving and "settle" in a sort of random place. They should not do that
    I see that this momentum behavior is also in the play head in the timeline. It really should not do that.
    Putting in a value in the dope sheet should be enabled, and it should automatically set a key
    I liked the visualizations of the easing, but it should probably be communicated with the keyframe's icon shape in the dope sheet like it does in AE.
    It is difficult to move a key to the beginning of the timeline.
    Architecturally, the preview rendering probably has to work the way it does in After Effects. Guaranteeing a real time visualization is pretty important.

I kind of stopped there because it's a bunch of goal-less fiddling. This is really great, there is a tremendous amount of product development. Hopefully you will think deeply about your audience and objectives, and the amount of product development that goes into After Effects.