R0k9pZfT
There has been a setting for ages (back to version 2.0 at least) to flip before the meridian. The ZWO implementation is however buggy - non-zero values tend to lead to crashing the scope into the pier/tripod. Great way to break something expensive.
So no-one uses anything other than 0, for which the meridian flip works reliably.
The implicit assumption is that your scope and mount are symmetrical east/west, and can reach the meridian on both sides, ie no gnarly ugly bits that stick out on one side and not the other. This is not always true.