Have some more pics, in general all is ok, buds swelling, a pistil here and there changing colour, no more signs of LSF, BUT there has been one issue which you'll see in one pic.
Basically, what you see in the "nasty" has affected the two highest fan leaves only, the rest of the plant is fine with no signs of anything wrong at all, not even a single yellow tip. I thought there was something up when these two leaves didn't "tilt" as much as before, and that's when I spotted it. So, my GoogleFu comes into use and, since it is limited only to the leaves that tilt up the highest, the assumption is that it's burn from the panel as they tilt up so they get somewhat closer to the panel than the top bud. Not touching, but "close enough". As I say, only the leaves that get closest to the light are affected which suggests to me that it's not a general nute or pH problem, especially as pH is tested across more than one part of the dirt, and I stick the probe in deep of course, and that has been constant in the 6.3 to 6.9 range since day 1.
So the affected leaves have been chopped and a VERY close eye is being kept on the rest to make sure it isn't something else