Excellent idea! That's how @rodrigotello/hnFollow works.
This way is slightly easier to customize, that way is slightly easier to manage updates.
In theory, Val Town could help users manage forks like Github does:
Or even notify users that they should "pull" from the remote val because it has new changes.
The question of when to use something as a dependency vs as a fork is a fascinating one. I'm eager to see what patterns emerge
I see importing as an installation method a val to my val.town account, while forking is just copying a specific version of a val.
I can see myself using, it depends as if I see myself as a user or a contributor.
Even for the same val, I can see myself having my prod endpoint and my dev endpoint.
Instead of instructing the user to fork the val, why not suggest the user to create a new val referencing your own ?
It would allow the user to automatically get update from your, or control them using the version query param.