>>15643745The Breast physics and deformers were done in a kinda lazy way for her model. Due to her impressive bust size the origin of the movement should come from the base of the breasts, since it has to move around all the weight.
But on her model the base of the breast barely moves and theres an abnormal amount of movement on the front part of the breasts, this is done to create a parallax effect and simulate the semi-3d effect, but it looks off since it moves like if the breasts had no weight to them at all. Almost like the front of the breasts is just lagging behind the model, which doesn't look that great.
My other guess could be that the inhouse model software that Hololive uses sucks at translating the physics from the Live2d files, since its a recurring issue with other software like Vtube studio and requires some fine tuning to get right.