Thanks :)
For the canoe animations, the paddle was attached to the character's left hand (it would move and rotate depending on the left hand) and the interpolation between only four keyframes for the left hand's poses was good enough. For the right hand though, only four keyframes were not enough, and its pose had to be adjusted on the paddle about every 5 frames (with 60 fps and 43 frames for that animation, this makes about 9 keyframes). Even then, since a 5-frame duration is very short, a little deviation from the desired place would make the right hand flicker, so it needed repeated adjustments. I considered letting Godot handle a smooth transition from the end of the animation to its beginning, but again, the interpolation it creates for the right hand could separate it from the paddle on the way back, or the hand could even pass through it. Well, thinking about time spent on the running animation, I could spare some more time but... :D