I'm using spacemacs for the convenience of largely not having to maintain my own emacs configuration, after 25 years of emacs use. For graphical frames and high-color unicode terminals, the fancy mode-line is fine.
However, I'm sometimes using a monochrome terminal, and the spacemacs mode-line is a lot worse on it than the traditional (emacs -Q) mode-line.
Is there a relatively simple way to toggle off the spacemacs mode-line for certain terminals?
window-systemis nil for a "character based terminal". To distinguish amongst terminal type, have a look at section 29.25 "Display feature testing" of the manual. I don't know the details of mode line handling for spacemacs but I guess you could change the value ofmode-line-formatbased on the found terminal characteristics..