Local variables aren't marked as unused, if you use a short declaration like this:
It is only correctly marked, if you use the following declaration:
local MAX_SPEED_Y = nil;
But then of course it also is marked as a redundant initialisation. It is not a big issue, but it can lead to some left-over code if you usually rely on the inspections-functionality.
Would be nice if this could be fixed for one of the future updates.