Technique Under Fatigue
The hardest, most important advanced skill is holding good technique when you're exhausted — because fatigue is exactly when form breaks and injuries happen. Studies show that as rowers tire, lumbar FLEXION creeps up (from ~75% toward ~90% of max range) even in skilled athletes, and head/neck control degrades too.
FilmableFilm this on your phone and TrueForm measures your body mechanics and tells you what to fix. You get angles, not a made-up score.