I too am suspicious of strong marketing and obscure technical descriptions!
However, I think the claim of improved efficiency here comes from the system being able to send heat to direct to radiators rather than via a heat exchanger, which probably is a benefit because heat exchangers waste some heat.
An efficiency improvement of "up to 50%" is claimed; maybe, but remember "up to" claims allow for 0% as well! I think how well it works depends on the circumstances.
Solid fuel boilers have a fundamental fuel efficiency problem, which is that the flame can't be adjusted to match demand. The fire burns even when no heat is wanted and although some is stored in the heat exchanger, the system avoids blowing up by wastefully venting heat. In contrast, oil, gas and Electric systems all stop consuming fuel once water is up to temperature, and only come back on when needed.
Solid fuel works well when the system runs more or less continually, or when the operator fires it up and down as necessary. A common arrangement is for a solid fuel boiler to cheaply heat a tankful of water, and then have an electric element or gas/oil boiler to cover top up demand. Efficiency is improved by combining two systems.
Cost and efficiency aren't quite the same thing. In financial terms, solid fuel is cheaper per therm at the boiler than electricity because there are no conversion costs. But solid fuel is poor at providing heat when and where it's needed. Most of the thermal value of cheap solid fuel goes up the chimney. In contrast, electric immersion heaters waste almost no heat, – far more thermally efficient – but the fuel is more expensive. When comparing heating systems, the per therm cost of fuel can be grossly misleading – an electric system might be cheaper because it only delivers heat where it's needed. At the moment gas is the best compromise: moderately cheap fuel with good automatic control reducing waste.
I don't have to worry about it. My home and lifestyle are completely unsuited to solid fuel heating! But solid fuel works well for others, who might take a punt on it. I notice the device hails from Eire where there are plenty of isolated homes and peat is a popular cheap fuel.
Dave