I’d like to create a macro to set a syntax, split the view vertically, and start a SublimeREPL instance for the syntax in the lower window. The Macro recorder does not record setting the syntax or splitting the view. Why?

Here’s a script I wrote that does what you’re looking for, for the R REPL:

gist.github.com/nicholasbloom/a … b2275b69c5

Just update the file with your REPL of choice (and you’ll have to change the command to put the window below rather than to the right), and add this to your user keybinding:

{
“keys”: “super+shift+r”],
“command”: “origami_repl”
}