Radiks is a server and could help to notify users as soon as the indexer has discovered new data that might be interesting for the current user.
Polling is usually not a good idea due to increased power and bandwidth consumption (https://nordicapis.com/5-protocols-for-event-driven-api-architectures/)
There is also a proposal for inbox on gaia. However, that is more for multi-user apps: Proposal: Gaia Hub Inboxes