I haven’t eaten much of those type of sandwiches. If I go to a deli, it’s more for bagels, lox and cream cheese. I just never thought the standard yellow mustard was anything great.

I wouldn’t even put mustard on my Costco hot dogs until they had deli mustard out on the counter, maybe 20-25 years ago. I like normal or spicy ketchup for burgers. No sauce on good steaks. In Indonesia they often serve lokal steaks with cheap BBQ sauce slathered on them. Not my favorite.

For ham and similar sandwiches, mayonnaise or Miracle Whip will do. I never root for the mustard to win the race at MLB ballparks, either.