No mate. I basically use a differing combination of cheese tomato butter and onion. Sometimes some pepperoni in to the mix but it starts to get all too complicated at that point. In the winter maybe some hot sauce.
I do sometimes do tunamelts where I guess you could see the mayo as a sauce.
If it's proper mature cheddar on toast then sound. Can't help feeling a wee bit of sauce will kick it off though.