(Didn’t looked into linked method nor file… but:)
If the array was a duplicate copy you have to make it single user under Object Data Properties and click on the number (with context menu: Dislay number of users…click to make single copy)…
Or do you wanna edit a single object in the array? The yiou have to apply the array modifier…
so you have to apply the modifier … ups… yes no i know the method… you have to something like apply the instancing… i wonder how this is done… newer heard anout this…
Ahh yes: Object make instances real: Ctrl-A ( or Object → Apply) and the Make Instances Real.
(Thank you i learnt something too.)