I am talking about scenarios where the user can't and should not be expected to know very much about Bitcoin

1. I don't think there is any situation where someone "can't" know that bitcoin has transaction fees of $60 or more.
2. If you don't expect every bitcoin user to know that, consider revising your expectations.

there should be no situation where the user is told they cannot participate

If someone can't afford to use the base layer, it seems fine to tell them "you can't use the base layer."