Hi! I do a LOT of admin customization. I do a lot of looking at the Solidus repo on Github, finding a hook to hook into with deface, and then if necessary prepending modifications to models and controllers.
You’ll also need to learn about whitelisting new attributes in config, if you plan to add attributes to models.
You’ll need to learn Ransack, if you’d like to add more search features, like for attributed you add, to the basic functionality and api, as well.
It’s quite the investment, but it’s worth it—full control. Which can be awesome for business-specific automation if a store gets popular, etc. Thinking about integrating ChatGPT to help with automating customers mails, recently—using a custom integrated mailers I created.