Someone mentioned to me offhand that “some are machmir” and are not eating canned tuna …
Would this be a case of being pretty meikil on kavod hamlachim by holding that you would be happy to feed canned tuna to the visiting melech (whether you interpret this as a President, a Governor, an Israeli prime minister, or Gadol b’Torah, or “just” a shabbos guest?)
Imagine, melech Shlomo is coming to your house and you proudly serve him a bishul yisroel tuna sandwich. He might just turn around and decamp to the nearby house that serves a halav stam cake …