Q: is there a way to set different scroll margins at the top and bottom of a window?
scroll-margin (defined in the C source code) sets how many lines of text that Emacs displays, at a minimum, at the top and bottom of a window:
Number of lines of margin at the top and bottom of a window. Recenter the window whenever point gets within this many lines of the top or bottom of the window.
I'd like to use
scroll-margin for the bottom of the window, but don't want it at the top (e.g., a positive value at the bottom, but 0 at the top). Is there a way to do so?