The Orea O2 is the larger O-series sibling to the O1: an open-bottom flat-bed brewer sized around 185 Wave and large Orea flat filters. It keeps the O1's direct, low-resistance drawdown, but gives the bed enough area and headroom for larger one-cup recipes or a true two-cup brew.
Because public O2 recipes are still scarce, the safest starting point is to treat it as a scaled O1 with 185-size paper. Use Orea's O1 and V4 open-bottom recipes as the reference: medium to coarse grinds, a steady 5 g/s pour rate, and pours timed by the water level falling close to the coffee bed.
A starting recipe: 24-25 g of coffee to 400 g of water, 92-94 °C, medium-coarse to coarse grind, five gentle spiral pours, and a 3:30 to 4:00 drawdown. If you brew with Wave filters instead of flat paper, start slightly finer; if the cup tastes hollow, tighten the grind before changing the pour pattern.