Penance I had briefly an Osmio, but it had a life of its own from unboxing. Turned itself off in the middle of pouring water but the water kept going. Sent it back to be repaired and when it came back, the thing still had a life of its own and kept turning itself on and off, so I got a refund. If you get one, once you commission it with about 10litres of tap water, it’s then a case of filling up the coffee machines water reservoir with the RO water.
In the meantime, I’m borrowing my neighbours Barista Hustle SCA water recipe which is working well. Tastes no different to the water I manage to tease out of the Osmio. Easy to make the recipe with bicarbonate of soda (from the baking aisle and some food grade epsom salt). Then you make it with a ZeroWater filter jug.
Or Waitrose Lockhills which I used to commission my Minima. Cheap enough and if you catch all the water in a suitable jug, pour it all back into the Lockhills bottle and use it for watering plants once cool/cold.