This would be very useful. I would argue for the universal link to go to the user's home instance, where the user should already be logged in and able to interact with the post. That is if the user has a default set. Otherwise the magazine's home instance makes sense for a unknown user.
It would be a core feature on activity pub itself though, with limited use on kbin.
What do we even comment on a story like this. In 2023. There are no words to express the distaste to how she was treated. Found her youtube channel and subscribed. Looks like she is doing cool stuff. Will keep an eye on it.