The Antetype-object is the same as the at-Variable implicitly defined in Script-Actions. Therefor you can use everything here too.
You can use the Cell ID, or find a DOM-Element and get it via the figure-property…
Could you elaborate what do you have in mind? Maybe we can find a solution how to reference a cell.
Sure, basically, I am thinking of a custom-popover for widgets with edit behaviour. Example: We have a configuration option for control sizes (macOS allows mini, small and normal for menus, buttons etc…). I set the control sizes via css variables in a widget that wraps around a palette (for example). Finding the top-level widget and changing its state is not very discoverable for new users. In order to make onboarding easier (like you have done perfectly in your tutorials), I am thinking I could just add a popover to a widget that lets users switch its state while still in edit mode.
Ah ok, then I think I misunderstood you. Using methods on Antetype only changes it in your current WebView/Browser but does not change it in the document (like change the active state in the Style-Inspector or Style Bar). We currently only have internal APIs to send the changes made by direct-manipulation (change size with handles, move cell to different container etc.) back to the application.