Luckily my day ended with a grounded male on the path near the lake - a detour I only took, as I was walking towards the exit, due to the previous couple of Knepp blogs which had mentioned the possibility of males coming to ground to visit the new path surfaces. So glad I bothered as I spent a good ten or fifteen minutes less than half a metre from a pristine male who showed full purple. Inevitably, I only captured more distant shots with him showing half purple as I got a bit over-excited and ran out of space on my phone, but I will add these at a later date when I've sorted out my google account.
Still, an amazing moment and I recommend anyone visiting Knepp checks out the area of path near the lake not far from the visitor centre. If I see no other groundings this year, I'll still be happy.
Good hunting all!