Technically, on UOX's side, this is working perfectly.
The problem is that on an AoS client, single click no longer exists while AoS features are enabled. Thus without the tool tips, you can still perform actions on Single Click (or do whatever you like, basically), as we are still getting a single-click packet.
However with the ToolTips enabled (which are enabled by enabling AoS features in the client) We don't get that single-click packet, ever. Rather we get a tooltip request packet, to which we respond with the proper information.
As for attaching an event to that packet, I would be hesitant since a person can set it to request that info on mouseover (that's actually default), Which would cause alot of requests on that event.
Well, wouldn't it be posssible to set it up similar to onUse, and allow the scripter to do a "return false" or true or whatever it is to return to code and make it continue there as normal?
Not really, we have 'NO' way of picking up a client single-click in an AOS client. The best we can possibly do is give you a way of changing the name sent to the client when the object is sent (which is when you come in-range).