Turns out I had nothing to worry about. At 70cm height and the lowest setting the seedlings loved it, I've turned it up and they are soaking it up.
I've moved the NL and the Sherbet into their mother tent with the Kingbo 300w blurple (actually want slower growth with these while the autos finish under the ISH3R).
Some pics;
Auto broiklyn sunrise Seedlings;
NL and Sherbet in mother tent;
I've got another NL seedling popped (it was a mistake, before I realised I'd finally sussed out how not to kill seeds!). It was stretching under the blurple at the height I had it so I've chucked that under the ISH3R to get it back in track. If it grows it will be too many plants for the space I have so I'll have to do something creative with it.
So what's the take away..... Grumpygrower was right, should have stopped all the fussing/over thinking and just let the magic happen!