Hmm, I guess it could in theory be done (though not for SoM). I'm having trouble seeing the usefulness of this though - could you elaborate on why this would be something anyone would want?
I'd rather just type /mount or /dismount... Idk, I'm weird. I have enough key binds to remember as is I guess..
If it's that much work obviously not worth it.
Now that I think about it though. If you did it that way you could even make it so you can specify what mount you want right?
Like /mount bree horse /mount blonde bay horse /mount harvest mount etc...