User self-service sheet subscriptions should have an "upon app reload" delivery timing just like in the Alerts feature. The strictly time based approach is very limited. The data could be stale or to avoid stale data the subscription has to come so late to not be timely or useful.
This was discussed as comments on this YouTube video: https://www.youtube.com/watch?v=gR6Wxlmj7G8&lc=Ugya7gBQGFcaA64MY1V4AaABAg.9Z2KX_v6BRX9Z4Zpsze3-M