Player with disabled shadows has an advantage over those players, who have them turned on. It's not good at all in compatible MP.
It wood be great if there weren't such an option as "Disabled" in shadows settings, only default setting sugh as
low,
standart,
high,
very high,
ultra
etc.
Another good reason to implement this:
http://feedback.arma3.com/view.php?id=1054