The problem I see with carts is that people can easily put a ton of supply inside they can use while others would just have to fight with their inventory. In longer fights it's clear that cart holders would be at a huge advantage.
For WS this sucks, but maybe a custom item with 8000 weight could be made to put in the cart. That way people can have their carts, but not any unfair advantage from it.
Removing the pecopeco is better imo since it gives LKs additional weigth limit increase, constant fast movement speed and removal on the spears size penalty vs medium. All those things together make an unfair advantage imo.