Does anyone know what the radius bonus on Spectral Battle Axe actually does?

Im leveling an acid/poison melee Witch Hunter right now and using some random Spectral Battle Axes. I noticed that my radius didn’t increase very much when I put on the second one. When I looked a little closer I saw that the radius bonus that’s a skill modifier has different wording from the “meter target area” wording of the base skill. It also appears as its own line item on the description.

I didn’t notice any double hits (if say the item skill modifier radius causes each target hit to release their own small echo). Is the item bonus bugged? It’s difficult to tell if the whole ABB explosion is bigger (comparing 4 meter radius to 4.6 is difficult to do by eye). Is the different wording just a tooltip oversight? Anyone know what’s up?

It just increases the aoe size of the blade burst, nothing else, no secret tooltip info, no double hits.

AOE size + 0.3 meters per axe.
Crit damage + 18% per axe.

One way to test the radius increase is to mind-control a cold-resistant enemy using Empowered Devil’s Charm, equip crap gear, then hit your mind-controlled enemy with ABB near a dummy. Progressively move away from the dummy then hit your slave each time until the dummy isn’t affected by ABB. Then equip the battle axes and try again. You only have 60 seconds to do this.

With a Crit +18% the 0.3m (less than 10%) really isn’t the main reason to pick the spectral axe imo, but granted it’s a small bonus.

I think the “Target Area” is a diameter, but if so, does not it increase by 0.6 meters with one axe?

Edit: Also one more question.
Regarding ABB’s Target Area, Spectral Battle Ax is “+0.3 Meter Radius” and Conduit of Night Whispers is “+0.5 Meter Target Area”. Do these target areas differ only by 0.1 meter in diameter? Why are there different expressions about expanding the target area?