I just came up with an idea, the code below does fix the override buttons update as well. (for rActionbar)
Not sure whether it taints or not.
Lua Code:
local updater = CreateFrame("Frame")
updater:RegisterEvent("UPDATE_VEHICLE_ACTIONBAR")
updater:SetScript("OnEvent", function()
for i = 1, 12 do
local button = _G["ActionButton"..i]
local texture = GetActionTexture(button.action)
if texture then
button.icon:SetTexture(texture)
button.icon:Show()
else
button.icon:Hide()
end
end
end)