ubiquitin
You’re right about there being things in the gemara, I guess my main point was the fact that it is in the shulchan aruch and poskim without any dissenting opinions among the rishonim. As far as I know it is a clear historical fact that the so called “minhag” not to eat some of the simanim was simply born of neccessity and thus does not constitute a valid halachic minhag.
The only siman whose identity is in any real doubt is rubiya. If this fact induces you to substitute carrots, be my guest. That’s not what I was talking about.
What I am saying is:
a) Don’t miss anything out just because your grandfather couldn’t get hold of it.
b) Making up your own simanim is cute, but don’t feel obliged to eat something just because your grandfather happened to be fond of a particular pun.