Please help, the edges of the new parts are not smooth

[Travis Cobbs]

If you're talking about the sharp edges on the piece in the back left (vs. the rounded ones on the piece in the front right), it's because there is no LGEO replacement for the piece in the back left. That means that the geometry from the LDraw file is used, and that geometry is significantly less high-quality than the geometry in LGEO parts.