Thank You. Click on first block, Shift-Click on Last block works – but one needs to be careful. I succeeded in adding a reusable block that contains multiple blocks.
But it feels delicate, flimsy – I can’t really put my finger on it why or how it could be better … maybe just marking the text all with the mouse and clicking “create reusable Block” would be easier, more robust.
I am a avid user of the keyboard (while typing my pages or posts I have both hands on the keyboard, grabbing the mouse takes time and breaks the flow) – so maybe [Ctrl]-[Shift]-[Down-Arrows] could select this block, pressing again would select next block … and the next block. [Ctrl]-[Shift]-[Up-Arrows] could select the previous blocks … I’ll go and see where to file feature requests.