Thanks for the suggestion.
I have indeed thought about creating flows in the Homey app (rather than scenes in the Powerview hub), but in the living room we have 4 horizontal blinds which we want to be able to open/close in all sorts of combinations (all, 3 out of four, outer blinds, inner blinds, 2 blinds on the left, 2 blinds on the right and each of the blinds individually). That would require a lot of flows, just for the living room. And the nice thing about Google Assistant voice commands is that you can use various device namings and alternatives (like up/down instead of open/close), see this thread.
But I could of course make a flow per room, to neatly “pack” the blinds when fully opened, e.g. “Pack room”, so that we don’t get the situation like in the picture below. I’ll do that for now to keep the wife happy 
