Plenty still to confirm here, of course. So, I had the lens focused on the stars equipped, and was messing around at the slags gate. On my last turn of combat I did a 5 length chain that ended in Stellar Focus, transforming the lens into the lens focused on nothing and granting 50 energy of Fluid Focus. I'd guess that the 5 length chain is important, not sure how important the specific form of the lens at the time was.
Edit: Took a while, but I was able to recreate this with the lens focused on minutiae. Took multiple attempts, then finally seemed to work when I had a 5 length chain, ending in Minute Focus, on the last turn of combat. I'm not sure that the chain ending in the focus tech is required, maybe it just has to be in there, but the 5 length and being on the round that ends the fight do seem to be required.