Well, a few days results, actual generally below forecasts but much better than before, have all been good enough to make sensible overnight charge decisions so far. Day 6 I went for 100% charge and ended up exporting 2kWh, rest of days shot for 80% overnight and on the backed off the charge rate to spread the charge time.
Solar Act. / Solcast F/c / WW F/c
3.39 _,./,. 6.54 _,./,. 5.1 _,./,. WW set back to 6kWp
5.68 _,./,. 7.52 _,./,. 8.8 _,./,.
8.47 _,./,. 13.67 _,./,. 12.9 _,./,.
8.35 _,./,. 7.66 _,./,. 9.4 _,./,.
13.44 _,./,. 20.5 _,./,. 23.8 _,./,.
7.97 _,./,. 9.9 _,./,. 6.5 _,./,.
12.31 _,./,. 17.87 _,./,. 15.3 _,./,.
7.5 _,./,. 9.31 _,./,. 10.01 _,./,.
8.02 _,./,. 13.48 _,./,. 9.8
UPDATE Lowered WW Solar kWp to 4.5 (rom 6 - This is a slightly north facing E/W split)
9.23 _,./,. 8.45 _,./,. 8.9
1.92 _,./,. 4.17 _,./,. 3.8
10.77 _,./,. 12.65 _,./,. 13.6
6.8 _,./,. 6.82 _,./,. 7.2
This is now close enough to be useful.