How is “compatibility” defined here?

A verdict of Compatible means the extension renders its frontend HTML correctly under Hyvä 1.3+, doesn’t inject Knockout or RequireJS dependencies, doesn’t break the cart or checkout flow, and survives a clean reindex + setup:upgrade. Backend admin behaviour is identical regardless of frontend theme — every status here judges only the storefront. So if a verdict says “Compatible”, you can install it next to Hyvä without porting work; if it says anything else, the row description explains exactly what gap remains.