Multi selection on non-continuous ranges

Currently we can only select a continuous range of blocks by holding SHIFT key.
Selecting multiple blocks by clicking with CMD key would allow operations like bulk move up/down, delete, style … possible without having to first move them into an adjacent position. Especially within a grid containing multiple items I find myself often re-arranging items, doing it one by one only is cumbersome.

I imagine that when you have node selection active and press CMD and the hover another node you see a hover overlay of that node, indicating you can select it as well (add to current selection). What should also work is select a continuous range first with SHIFT and then deselect individual items from this selection.

Start by tracing the existing node-selection handling and the SHIFT continuous-range behavior described in the issue. Check how hover feedback and selection state are represented, then verify that CMD-click adds and removes individual nodes and that bulk operations work across the resulting selection.