True, but it's still too big a risk for the Reapers to take. Anyone paying attention would have wondered why nobody ever returns from the Omega-4 Relay, and would have started researching why it kept happening. Eventually someone would have theorized that the relay might lead to someplace where the standard drift of several thousand kilometers could prove fatal, such as an asteroid field or a highly dangerous area like the galactic core. Then maybe they would have sent some sort of unmanned ship with a mass effect drive to traverse the relay and send back data before it was inevitably destroyed.
The basic point being: it makes no sense if you look at it from an in-universe perspective, leaving the only rational explanation for why the Omega-4 Relay looked so different being "it looks cool."