I know you can use
C-c C-c) to execute individual code blocks, but is there something akin to "Run all chunks above" that RStudio has for Rmarkdown files?
You can easily run all code blocks via
C-c C-v C-b, or all blocks in a subtree. I don't think above this point is implemented.
It would be fairly easy write a custom function that takes all text below the point, hides it, executes all code blocks, and then restores the text. I would do that rather than taking all text above the point and executing it in a temporary buffer, because some code blocks may use the buffer-name or file-name so it should not be changed.