I'm not sure a connection plugin makes sense, since it requires
transfer of files to/from the target, though possible via the terminal
i don't think this is a good approach.
One option to send commands is using the expect module (delegated to
the host having terminal access) to handle commands and prompts as
they happen
Another is creating something like the telnet action plugin that will
handle the communication directly and allow you to send commands (its
mostly a specialized 'expect').
This brings back memories about kermit and zmodem from 25 years
ago … has anybody thought about integrating one of those with
Ansible, already. Sounds like a real niche application, though.