I might be minority, but I am not that surprised by the results or the not so significant GPU hours. I've been video segment tracking for a while now using SAM for mask generation and some of the robust academic video-object segmentation models (see CUTIE: https://hkchengrex.com/Cutie/ presented at CVPR this year.)for tracking the mask.
I need to read SAM2 paper, but 4. seems a lot like what Rex has in CUTIE. CUTIE can consistently track segments across video frames even if they get occluded/ go out of frame for a while.