though I thought that the standard ZC process was to add item, add option name to item, add/activate option value(s) to item.
Well, in a sense it is; but before doing that you have to create those names and values. I understand that this is usually not the case of usual zen admins, and since is a bit unusual, that's why I asked. Usually you don't set same option values to different option names, but even different industries I can see that it could be the case.

Zen Cart even have an option to copy/delete options from an item to another (which I've never understood, and don't know even if it works), I do believe they should have done a copy all the values of one option to another...

I will try your suggestion and report.