Any chance of getting native support for Serial (DB9/RS232) communication in Windows Terminal? Would love to use it but I'm still using PuTTY and HyperTerminal.

Is there not a suitable CLI or TUI client for Windows that can simply be called from within Windows Terminal? Honest question. I just know that on Linux, it'd be really weird to ask for my terminal emulator to embed a serial client rather than call e.g. screen or minicom from my shell.

I think it has been discussed but not implemented yet. In the meantime, tools like https://github.com/fasteddy516/SimplySerial give what you are looking for instead of those alternative GUI tools.

I recommend Tera term. https://github.com/TeraTermProject/teraterm/releases

As much as I like PuTTY the ergonomics for "monitor this port as I plug/unplug the USB-to-Serial adapter" are so much better in TeraTerm.

Indeed. Plus some serial file transfer protocols. At least xmodem, ymodem and kermit.

Is there something lacking in PuTTY ?

The PuTTY terminal has a few more features in certain areas but a lot fewer features overall. Also, of course, PuTTY does not share profiles/settings/window tabs+panes with WT, which is a bit of a pain.