Increasing the ability limits on items

I'm trying to increase the number of abilities that can be put on items from 4 to a maximum of 6.

Is this even possible?

I've been digging around with the search engine to no prevail, but I got a couple item systems being downloaded, namely AAA and BX-TRSII, right now. But I haven't came across a line of text saying "Allows many more abilities on items" or the like. So, again... is it possible?

adding abilitys to units that aquire an item, and removing the abilitys when they drop the item. Rather simple in idea, a bit more complex in implimentation.

I sometimes use spell books for this.