[MunkDev]

Originally Posted by DashingSplash Was really surprised to see that local prefix = SecureButton_GetModifierPrefix() local binding = GetBindingAction(prefix .. key) was a thing. Although, I assume I'll get a better understanding of the API with some experience.

I didn't really know this either, but given a copy of the UI source code, there's a method to finding what you're looking for by going to the source of something you want to modify and looking at how it works. If you haven't already, get a copy of the source code and use an editor that allows you to search in the code for the things you're interested in. In this case, it seems likely that Blizzard would at some point implement a utility function that returns the current modifier chain, because it's useful in a lot of cases.

Originally Posted by DashingSplash The only thing that had to be included in your code was to allow companion, item, and macro functionality. See modified function below. Any input on that?

I would actually use a table for this, partly for code clarity, and also because it's easier to modify on a whim.

local dismountTypes = {
    spell = true,
    item = true,
    companion = true,
    macro = false,
}

if HasAction(action) then
    local actionType, spellID = GetActionInfo(action)
    
    if dismountTypes[actionType] and not protectedSkills[spellID] then
        Dismount()
    elseif actionType == "macro" then
        spellID, _ = GetMacroSpell(spellID)
        if spellID ~= nil and not protectedSkills[spellID] then
            Dismount()
        end
    end
end
return

Originally Posted by DashingSplash The only thing I am unsure about is how button = stanceButtons[binding] if button and not button:GetChecked() then       Dismount() end works. When and how is the button state set to checked?

I'll give you an example of how to track execution path in this case, which I don't think any tutorial brings up. If you look in Bindings.xml, you'll find that e.g. SHAPESHIFTBUTTON1 is calling StanceBar_Select(1). A quick search for this function gives you this result:

-- Searching 1364 files for "function StanceBar_Select" (case sensitive)
-- UISourceCode\StanceBar.lua:
function StanceBar_Select (id)
    StanceBarFrame.lastSelected = id;
    CastShapeshiftForm(id);
end

Casting the shapeshift form generates an event that updates the stance bar, which results in the current stance active having its button set to checked.

function StanceBar_OnEvent(self, event)
    if(event == "UPDATE_SHAPESHIFT_COOLDOWN") then
        StanceBar_UpdateState();
    end
end
 
function StanceBar_UpdateState ()
    ...
    if ( isActive ) then
        StanceBarFrame.lastSelected = button:GetID();
        button:SetChecked(true);
    else
        button:SetChecked(false);
    end
    ...
end