Have you considered WooCommerce?
There are a large number of plugins that integrate with it and it is highly customizable with a long list of hooks and filters.
I’ve never tried the Restaurant Menu plugin.
You can always install it on a local machine and put it through its paces ??
Sometimes niche plugins can offer amazing functionality and they can be ve y well-supported.
The important bit is to vet them thoroughly to make sure that they are the right solution for you (/your client).