Yeah, I kept momentum tricks in the game for a long time because I love how they reward players caring to details. The bad thing about it, is when a new player triggers momentum tricks by accident, it it very disturbing an unnatural.
I really think there is now enough tricks for high level play (short hop, tech, wall-jump, fast-fall) to not rely on things that can kill uneducated players.
In the case of neutral special, the hard nerf is on purpose. Online play was only a mater of pushing the opponent to the edge, and edge-guard with sliding neutral special. I would have loved to keep an effect with momentum, but as a strong kill-move, it has to be punishable easily. Having it fixed in time, and movement allow the opponent to react as soon as the charging animation starts. This is an early kill move, and requires an hard-read to be placed efficiently.
Above is my reasoning for the changes. I sincerely think they are good but certainly can be improved. I would be glad to discuss the movesets in details on the Discord if you are inclined to join.