Thoughts on toggling a toolbar when on a warsteed?

[Delone]

From the Rohan prelim notes posted here:
http://www.lotrointerface.com/forums...ead.php?t=1862

I see:
• Added GetMount to LocalPlayer.
• Added Mount, BasicMount, and CombatMount.

If I've been using this to toggle a UI quickslot bar on/off when in combat,

self.player = Turbine.Gameplay.LocalPlayer.GetInstance();
AddCallback(self.player, "InCombatChanged", function(sender, args)
self:SetVisible( self.player:IsInCombat() );
end);

What would be the correct structure for changing this to work to toggle the quickslot on whilst using a CombatMount given the above information?
On Bullroarer, replacing "InCombatChanged" with "MountChanged" works to trigger an event when I mount and dismount (either a normal mount or a warsteed), but can't work out what to use to get visiblility of the quickslot to change in place of (self.player:IsInCombat)
Any suggestions?