No, the difference is that if you pass to Solid's <For> a signal to an array, and make a node for each of the values of that array, and then you change the sign

No, the difference is that if you pass to Solid's <For> a signal to an array, and make a node for each of the values of that array, and then you change the signal to point to an empty array, then Solid just deletes those nodes and they eventually get garbage collected, if you then pass the signal an array containing some values then new nodes are recreated. The difference is that in Voby, if you explicitly opt into this, nodes are not deleted but kept in memory when going to an empty array, and new one are not created when going back to a non-empty array, those nodes kept in memory are repurposed. As a rule of thumb if you don't have any API for explicitly opting into recycling it's not happening, it's not a safe optimization that can be applied all the time.