Couple of tips if it helps, when you lay it on, aim to get it on at a rate of say 1sqm per minute, not hard to do if you get into the zone. You’ll then cover the whole wall with loads of time to spare. Lay it on in fairly straight long strokes up/down, rather than going all over the place with random directions. Try to keep it relatively tidy as you lay on - smaller lines are fine, massive thick bead lines not so good - smooth ‘em off as you go.
As Soon as first coat on, wash tools, relax, and flatten it in straightish strokes which should be very quick to do. Quick run round with Water brush around the edges to stop them getting crusty and keep them clean.
Whole thing should then feel fairly “under control”, and personally I’d then hold fire until it feels like it’s really firming up before repeating the whole thing with a second coat. More likely to lose things like visible board joints that way.
Speed skims/spats etc are good, and I love mine, but you shouldn’t really need one for areas that size and it’s much better to Iearn how to get it right using just the trowel first.
Edit: just noticed I’m 2 weeks too late. But I’ll leave this here incase it helps anyone else.
