[Walkerbo]

I have now accepted that I will have to dismount after the player has mounted.

To do this I have the following chunk:

local f = CreateFrame("Frame")
f:SetScript(
    "OnEvent",
    function(self, event, ...)
        if event == "UNIT_SPELLCAST_SUCCEEDED" then
            unit, spellGUID, spellID = ...
            print("UNIT_SPELLCAST_SUCCEEDED", unit, spellGUID, spellID)
            for k, v in pairs(C_MountJournal.GetMountIDs()) do
                if v == spellID then
                    print("found")
                end
            end
        end
    end
)
f:RegisterEvent("UNIT_SPELLCAST_SUCCEEDED")

I cannot work out why I never print found, but maybe I am too close to see the error.