After using the cover the algae was dead within a week or two
It’s early days for assessing heating, but the pool temperature has risen about 6 degrees in a week, now the sun has come back, so I have high hopes.
Aesthetically, the dark blue colour actually blends in very well and is far less noticeable than I thought, even in a natural setting with pool vegetation.
In summary, an excellent product. Controls algae in the most challenging of circumstances!