"no amount of prefixing will help you, if random app enforces the limit"
I've noticed that, it's partially the reason for my confusion (I didn't wake up for quite a while as I put it down to the different versions of Windows I was running on various machines). Other pains are caused by apps that still don't run Unicode and crash or stop copying when they encounter a non-ASCII character.
Many apps do something like
char path[MAX_PATH]
In that case, no amount of prefixing will help you, if random app enforces the limit.