Layer index when inserting block elements

[EGRoBBeRTiT]

When you insert canvas elements, they are inserted on top of all others. However, when inserting blocks (an image or a note), they are inserted under the canvas elements. Is this behavior good for you or not?
It seems that any element that is inserted must be on top of all the others.

I found a block of code where the index for the block is generated if the last layer type is canvas. It is located in packages/blocks/src/surface-block/managers/layer-manager.ts:

      if (lastLayer.type === 'canvas') {
        const secondLastLayer = nToLast(this.layers, 2);
        const secondLastLayerIndex = secondLastLayer
          ? ungroupIndex(secondLastLayer.indexes[1])
          : null;
        const lastLayerIndex = ungroupIndex(lastLayer.indexes[0]);

        return generateKeyBetween(
          secondLastLayerIndex,
          secondLastLayerIndex && secondLastLayerIndex >= lastLayerIndex
            ? null
            : lastLayerIndex
        );
      }

Here you take not the last index of the last layer, but the last index of the penultimate layer (which in this case will be of type block). At the same time, you forgot to check that the penultimate layer exists and this occurs when you generate a key between null and null.
If the penultimate element exists, then an index is generated between the last index of the penultimate layer and the first index of the last layer, or null. That is, you deliberately position the blocks under the canvas elements. Why did you do this and is this normal or did you make a mistake?