Keeping to the area denial theme of this spell, maybe it could just automatically try to turn any undead in the area once per round.
I think it should also just be a feat that uses the same check as Warding Gesture, perhaps requiring it, since without all of the turning feats, this would be useless, and a small fraction of Clerics take those feats as they don't mesh well with the server environment; healing & direct offensive/defensive bonuses are always more attractive than making your party chase undead around dungeons you are already able to overpower easily.
Maybe if there were more slow-moving zombies at high level, turning would be invested in more often. But most people are happy with fighting enemies that just stay put and die, and in my experience it frustrates people more than entertains them. When Shannon was still a new character and had the wrong domains for her god (Healing/Repose) people would complain about having to chase them down, sometimes even in OOC chat, despite some of the undead dying on the spot while others fled. Realising my support character was unhelpful to play with was one of the reasons I ended up getting a remake even after correcting her domains.
So while protecting oneself from undead by fearing them looks like a great tactical option, this isn't PnP, so you don't get XP for routing undead, only defeating them, and people are in dungeons for XP. In a DM event, or facing off against A/MPCs, Warding Gesture (and this hypothetical area denial version of it) is probably going to be more useful.
Area denial is different because it could be useful in niche situations, or to turn around bad fights. Maybe if the consecrated area healed people, harmed undead, etc. based on Charisma bonus, or granted people extra damage (AOE Divine Might), you'd be looking at something people would actively want to take.
The actual area denial spell is called Aura versus Alignment. It's only available to high level Clerics, but it's one of the only non-MAD deterrents a Cleric has. A feat which mimics even some of its effects (saves, AC, reflect damage, spell resistance) for a brief time but is anchored to a specific area could end up being a popular alternative/supplement to the direct turning feats.