Interesting! Congrats on the launch.

I tried it out, and just first feedback:

- I often use the "Home" and "End" key to go the start/end of the line when I'm editing a cell. It scrolls to start/end of the whole spreadsheet, however. Since I'm not a spreadsheet user, I'm not sure if that's expected.

- The handlers like "on_dropdown_change" should receive an argument for the cell it's coming from, so you can e.g. change the cell that's next to it. Or how else is this supposed to be done?

It's quite cool :-) I suppose one problem could be integration with existing Google Sheets / Excel sheets?