Script PTYs started at 0×0 under Erlang ports, so tools truncated and paginated as if the window were tiny. Always wrap PTY children in a runner that stty-resizes the slave to the host size (from stty size), and export COLUMNS/LINES. Keep a long-lived stdin mux for the raw REPL so post-command history keys are not dropped after PTY relay or interrupt watch. Prefer capture with nested pagers forced to cat for normal externals; page long output through the builtin pager in the interactive REPL. True TTY programs (vim, htop, sudo, ssh, …) still inherit the terminal.