Maybe someone can correct me if I"m wrong, but I don't think this is possible currently. You could open a case with F5 Support to request this type of functionality. For now, maybe you could use global aliases to simplify your initial setup?
Alex Applebaum wrote a codeshare example on global aliases in tmsh:
Okay, thanks. I'm aware of aliases, but was looking for something that could run every time an automated process logs on, so that the process doesn't have to be aware of the change from bash to tmsh in newer versions.