Hi there,
If you can move on to your theme JSON files, then you can save the customizations you have made. All you have to do is copy the contents of those files from your previous theme to your new one.
In the templates folder, you don't have to move all, but some that are important, like the ndex.json, which is the homepage, product.json, etc.
If you have done code changes to your store, then of course, you have to move those codes as well.
Let me know
