I've drawn a line with the pen tool which is supposed to come on to the screen from above with a fast speed which decreases when it reaches the middle of the screen, then I want it to grow further at a consistent slow speed to the end of the screen. What I did so far is to set two easy ease keyframes, the first at 00:00:00 (0% End in Trim Paths Settings) and the second at 00:01:00 (50% in Trim Paths Settings). Is there any way to achieve such a motion? I've tried to set additional keyframes after 00:01:00 (either usual or easy easy ones) but there is always a slight interruption in the movement which doesn't look good at all.
selecting the keyframe, then choosing animatino>keyframe interpolation (or right-click the keyframe then choosing the same option) and then setting the temporal interpoaltion to 'auto bezier' usually does a nice job of smoothing motion through a keyframe to ramp dowm/up speed like you are doing.
you can also option-click (mac)/alt-click (win) the keyframe to toggle auto bezier and linear for a keyframe.