This is more the question for softwareengineering.stackexchange.com . "On the other hand it could cause some unexpected side effects." - that's it, this should be avoided at all cost. You can keep a common reference instead of copies but make sure you don't do unwanted changes to it. Notice that global stores (Vuex, etc) discourage direct mutation of a state for this reason, mutations are explicit. — Estus Flask just now

This is more the question for softwareengineering.stackexchange.com . "Do you have a general list of objects of a given type in your store and retrieve a reference from it when you need to assign it to another object" - sounds like premature optimization, should be a concern, unless you know beforehand this will be a problem for performance to store too much dupe data. Then it's probably a case for changing data structure instead to be more efficient, e.g. Normalizr — Estus Flask 19 secs ago

"Do you have a general list of objects of a given type in your store and retrieve a reference from it when you need to assign it to another object" - sounds like premature optimization, shouldn't be a concern, unless you know beforehand this will be a problem for performance to store too much dupe data (probably needs to be cleaned up from ram when unused). Then it's probably a case for changing data structure instead to be more efficient, e.g. Normalizr. This is more the question for softwareengineering.stackexchange.com — Estus Flask just now