The purpose of the '-n' switch is to prevent the value, after regular evaluation, from being interpreted as a calculation.
I can't check right now, but I'm sure /var -g still calls /set several times as is typical of /var. Having all extra switches supplied with -g passed on to /set would be trivial to implement and would improve the command, imo.
(I couldn't follow the thread on my phone very well so apologies if I missed something :p)
