When you change from unpacked to packed as the Queen of Thorns, your displayed character stats work as normal. But when you click to change back to unpacked from packed, it does not update your weapon data. This is because in:

\sim\BuffAffect.lua:Line 208

Whenever this line is called, (aside from before the QoT does her first state change) it continuously returns the packed weapon as being the primary weapon even when she is in her open form with the packed weapon disabled. I am pretty sure that this is handled deeper than I can mod, since I am assuming (though not sure) that the weapon is getting set as primary when the MANUALWEAPONDISABLE buff is called. I couldn't find anything that set the primary weapon >.<