Warp is a terminal, we still rely on the underlying shell to do the interpretation / execution of the commands. At the moment, we support using bash, zsh, or fish as the shell.
Writing a tty which has to support specific shells isn't confidence inducing.
How did you paint yourself into that specific corner exactly?
I'd be more careful about the messaging then, something like "you can use any shell you want, we provide enhanced features for bash/zsh/fish and are looking to expand that in future".