[Symbiote]

This is true for the British system, except for the largest houses (6+ bedrooms) where you'll have a three phase 415V supply.

Elsewhere in Europe it varies. Even small properties in Denmark and I think Germany have a three phase supply, my oven and stove use it directly.

[angry_octet]

There are multiple circuits on each phase, you would still need to limit current per outlet to 10A (8A sustained). If it's a dedicated circuit then 15A is fine, but usually that means a separate run, and in that case you can just have 20A or 32A.

When you have "three phase 415v", the 415v is the phase-to-phase voltage. Unlike the US 180 degree split phase 220v or 208v p2p, consumer equipment is not wired phase-to-phase unless it is 3-phase.

It's interesting that Europe has 3 phase cooktops, we usually see 32A single phase in Australia, homes rarely need more than 7kW per circuit. Aircons, pool heat pumps and EV chargers are the 3p loads.

Getting a 3 phase PV inverter is worthwhile if you have sun synchronous loads, like pool heater/chillers, across the phases. Then you will want a 3p battery inverter for the same reasons.