It seems like you’re grouping a bunch of things together and saying I have opinions about them that I don’t. Let’s break them out:
workflows I would assume to be portable, yes. It is an assumption. I generally expect program configuration to be mostly cross platform by default.
I’m not sure what a program written for a particular terminal would be, so I’m not sure if I’d assume portability or not.
Shells are not ubiquitous, even if they are available across platforms technically.
Python is truly cross platform and largely ubiquitous.