Removing disarm is dumb but I can see why people want the investment protected. They could make it so once you pick up the weapon, you get some flavor messaging. Like, "You pick up a broadsword. You recognize this weapon as (name). You last recall seeing them in the area of (last known town characters interacted or were)." Chances are you're running past or looking at a character. It makes sense to link a registered weapon to the owner in some RP form.
Make a weapon that you actually own stick out when you register it or something.