That should be entirely possible and an agent using the skills and the example blocks from the shared theme should be fully capable of coding this.
I actually did a similar block a while ago. It’s not yet using the new Blocks API, but you could still look at the approach at Manuel Kostka / Discourse / Blocks / User Profile · GitLab. Looks like that for example, on the Canvas Central theme:
We don’t have blocks in core (yet). All blocks are just added using themes or theme components.
You can add blocks to existing BlockOutlets using themes and theme components and I think you need to be on a Pro plan or above to add custom themes. Else there should be no limitations.
