The request
“I already upgraded the theme with you in the past and I'd like to do it again. We did custom coding that uses features in the current version and it needs to come with us.”
A repeat update from a merchant who knew the drill.
The approach
We updated the theme on a duplicate, carried each customization forward using our records from the previous update, and tested before publish.
What we shipped
Theme updated to the latest version
Customizations carried forward from records
Tested on a duplicate before publish