Nice work and good pup. If it were my pup I would (talking bout 1st vid),
1. Keep my hand attached to my waist level for engagement and food reward (not move hand up or forward/ahead of my body).
2. Lose the "stay" cue (meaning flashing your right palm). Dog knows and will maintain position till you release without the extra command and hand motion (short durations at first).
Good job, keep it going and engage, engage, engage with many play type routines.