nvim scroll and screen draw speed slows down immensely when in butterfish shell

[alichtman]

In a regular zsh session, Ctrl-D to scroll works ultra fast. Inside a butterfish shell, it's noticeably laggy. Use the following command to start nvim without sourcing a user config:

Sample file: https://github.com/alichtman/dotfiles/blob/main/.config/zsh/.zshrc

$ nvim -u NONE ~/.config/zsh/.zshrc

$ nvim --version
NVIM v0.11.0-dev-1376+g738320188f
Build type: Release
LuaJIT 2.1.1734355927
Run "nvim -V1 -v" for more info

$ butterfish -V
 linux amd64
(commit ) (built )
MIT License - Copyright (c) 2023 Peter Bakkum

(It's butterfish v0.2.15 -- which should likely be in the version output. I installed it with $ go install github.com/bakks/butterfish/cmd/butterfish@latest)