Hi there @Alan_
Thanks for getting in touch and describing your potential use-case around how apps could work with merchant-specific content. I've communicated this example and suggestions on to our internal developer team, and we’ll work on finding a solution to this. I'll update here when our developer team has explored this further.
Just to note on your potential approach that apps could dynamically add/update sections via the Asset API- this is something we would not encourage as it could have unpredictable effects on the theme, and as you noted there could be issues around portability.
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