na=\"nil\" in ob-R.elo

[Brett Presnell]

Probably a silly question, but in ob-R.el, what is the reason for
setting na=\"nil\" when defining org-babel-R-write-object-command?  Is
this an elisp compatibility thing?

Regardless, I generally (always?) want na=\"\" for this, so I am finding
all those "nil"s very annoying, and the only way that I see to defeat
them is to redefine org-babel-R-write-object-command.

If there is no reason for the current behavior (doubtful I know) and if
I am not missing an obvious work-around, then I would like to suggest
changing this behavior.  Otherwise, would it be feasible to add an
option for R code blocks (:nastring?) where one could specify the NA
replacement string?

What do you think?  It's easy to suggest I know and certainly beyond my
elisp coding skills at present, but I am supposing that someone more
fluent in elisp could do this safely without too much trouble.