Selfbuilt- I'm fairly 'new' here, but I have to say, you post a hell of a review!.
Being a big believer in comparative beamshots, you answered a lot of questions for me with them.
This pullquote tells me a lot:
"Clearly, the TK45 is not a great thrower – you wouldn't expect it to be with this design. But it does have one of the smoothest and most even beam profiles I've seen in a high-output light. If you want a "wall of light," this would be a good choice."
Fortunately for me, I want walls of light and a couple of throwers for my trade.
Yes, separate heads make a difference because if you do a test that shows a beamshot of each head alone (covering the others) you'll find that the heads are probably NOT parallel, as is commonly the case with co-located reflectors. That's how the daisy overlaps are avoided! This is the right way to deliver beam that's useful close up.
Eventually, Fenix will enclose the array in something 'circular' for aesthetic finish, but obviously it's not necessary.
I take it the TK45 blows the TK40 away? I would appreciate a side by side of the beamshots and side-view to show relative size.
I use these lights for photography primarily so I'm always keen to know how the new lights compare to what I'm using now.
I see FENIX as the next leader in flashlights in about 2 years. MAG ought to buy them out before it's too late.
Great job!