Just as an update, I finally got some time to descale my 2 year old Bianca, used with Lockhills exclusively. Not the greatest photo, but you can see some scaling on the underside loop of the element, but not too severe(?).
After 4 hours it looked much better.
I followed this up with the official descale method using the purly solution mainly flushing the service boiler.
Looking at the scale built up over two years, any thoughts on whether it warrants a descale every year, or stick to two?