It sounds like the EGR is on the way out, my 147 began with brief power-loss which took a month or two to turn into a near constant problem. Cleaning the EGR sorted it out for a couple of years or so, I've repeated the clean but think I'm going to have a remap to delete it soonish.
Low mileage doesn't seem to suit a diesel engine, if it doesn't get hot carbon is deposited causing (in part at least) the EGR problem and further blockages elsewhere. First time I cleaned the EGR was at about 30K and 4 years old with lots of carbon present, second time was about 80K and corrosion in the EGR was the problem rather than carbon, I expect a new EGR would have lasted much longer.
Simply unplugging the electrical connection to the EGR should show whether it is causing the power loss as it will never open, you will see an error code on the dashboard though so not a long-term option.
Having the EGR deleted in the map is, I'm sure, the best solution, personally I'd be happy with just that and no power increase but it doesn't appear to be an available option.
Give a man a fire and he's warm for the evening.
Set a man on fire and he's warm for the rest of his life.