Question About Sell-able Items Per Business Type

[TimeRupture]

So i have seen people say they sell cigars and liquor at their supermarkets, however in the F1 tab the game doesn't list these items as sell-able items in a supermarket.

My question is can you actually sell items in your stores that isn't listed as sell-able in the F1 tab?
Id love to shove a bunch of things in one store, like a Walmart

[Kyle]

yes but it's reduced i'm pretty sure

ie my liquor store does sell gifts, but not nearly as many as my gift store

[David Estes Creations]

You can sell any retail in any retail store, but the "main" item(s) will sell better than any extras.

[Huzaberg]

I put cheap jewellery in my gift shop and didn't sell a single one, seems odd as jewellery is often found in gifts shops. I did it IRL xD