You may want to look into the Zebralight H600Fd III. Beautiful flood headlamp. The Acebeam is over $100, the ZL is $89.00. I own Nitecore, Skilhunt and Zebralight. The ZL is the better by a good margin IMO. They are backordered on ZL website, but they usually get them in every few weeks. Email them, they might slide one out the door for you.
I love my Skilhunt H03R well spaced modes you can choose for each of the 4 modes 2 levels of brightness
It has a timed stepdown
But as it uses a buck driver the losses on it make it hard to get the full brightness on turbo, on 490 lumens its great, but Turbo wont be much brighter than the stepdown after the cell gets to 3.8V