Conditions using attributes from relationships

[Taylor-Mudd-9fin]

Hey folks, I wanted to suggest a feature that would really help us out, alternatively if there's a nicer way to model this currently please do shout!

I have an example scenario

type user
type group
    relations:
        member: [user]
type folder
    relations:
        read_access: [group#member]
type file
    relations:
        folder: [folder]
        view: read_access from folder

Now what we want to model is a user losing access to a folder should retain access to the files within it up to the point of access expiration.

We've looked at doing this by putting a condition on the folder access with the date they lost access and can correctly enable/disable access to the folder based on current date using that.

We've experimented and can store the date the file was created, but what we can't do is the specific file access part. I believe this is because you can't use a condition where the contextual tuple lives on a relation?

Is this something that could be considered for addition, or there another way to model this?

NB: Our fallback is granting direct access to each resource when access is lost but we're a little afraid of our tuple count exploding so exploring other options