The demo is neat. How did you do the backend? As far as I see your offering is only related to the UI components. What databases and backends are you seeing users have success with?
We are agnostic to back-end frameworks. Some users have used Prisma + Graphql, NoSQL databases etc.
The Sheet data structure on the UI can be flexible too. It can come from streaming data source, lazily loaded on-demand or all stored in browser memory